Your State's Algal Bloom Advisory Was Not Written for Your Dog

There is a number for your dog. It is not the number on the sign.

Oregon publishes both of them in one document, one near the front and one in an appendix. In its Advisory Guidelines for Cyanobacteria Blooms in Recreational Waters, updated May 2024, Table 2 sets the recreational use value for microcystin at 8 micrograms per liter. Table C-4, in Appendix C, sets the dog-specific value for the same toxin at 0.2. For saxitoxin the two numbers are 8 and 0.02.

Then the document explains which one gets used:

“OHA has also developed dog-specific RUVs. They are for informational purposes only to educate pet owners about the susceptibility of dogs to cyanotoxins and are not used as a basis for issuing public health advisories.”

And Oregon’s public FAQ says the same thing in one sentence: “OHA has established RUVs for people and dogs, but advisories are only issued when there are human health concerns.”

That is not a criticism of Oregon. Oregon is one of the few states that derived a dog number at all, published it, and told you plainly what it is and is not used for. Most states have not gone that far. The point is what it means for the sign at the boat ramp: a posted advisory is a statement about people, and reading it as a statement about your dog is a category error that the issuing agency has already warned you about.

This page is about that gap. It covers freshwater cyanobacteria, also called blue-green algae, in lakes, reservoirs, rivers and ponds. It does not cover marine or coastal blooms, red tide, or the airborne route that comes with them, and the last section explains why that boundary is real rather than tidy.

What This Page Is Not

Two disclaimers first, because both matter more than usual here.

This page holds no live data. It cannot tell you the status of your lake today. Nothing here updates, nothing here is fetched, and if you came looking for a green light for a specific waterbody this afternoon, the honest answer is that this page cannot give you one and neither can any national source we found. What it can do is tell you where your state publishes its own status, what the words on that status mean in your state specifically, and what the status is measuring, which turns out to be the part most owners get wrong.

This site has no veterinary reviewer. You will find sourced veterinary facts below and a clear get-to-a-vet trigger. You will not find treatment, dosing, or anything to do at home to a sick animal, because that is veterinary work and this is not a veterinary practice.

The Federal Numbers Are Human Numbers, and EPA Says So

Start with where the numbers come from, because almost every state either adopts the federal values or builds from them.

In 2019 EPA issued recommended recreational criteria for two cyanotoxins. EPA’s current page on those criteria, last updated June 24, 2026, describes them this way: “The Agency has identified recommended concentrations of these cyanotoxins at or below which human health is protected while swimming or participating in other recreational activities in and on the water.” The values are 8 micrograms per liter for microcystins and 15 for cylindrospermopsin.

Two things about that sentence deserve to be read slowly. The first is human health. The second is recommended. EPA continues: “States, territories, and authorized Tribes can consider adopting these recommended criteria into their water quality standards and using them for Clean Water Act purposes. Alternatively, they can use these same values as the basis of swimming advisories for public notification purposes at recreational waters.” Can consider. This is not a national standard that binds anyone.

The underlying technical document, EPA 822-R-19-001, is even more explicit about the scope, in a sentence sitting in the middle of the derivation:

“While there are examples in the literature and reports of animal poisonings and death due to exposure of cyanotoxins, values protective of animals such as dogs and livestock are not generated in this document. However, section 7.8 discusses some animal-specific issues, including a summary of guidelines that several states have developed for animals.”

We are quoting both sentences on purpose. The second one is the reason this page exists: the federal document declines to produce an animal number, and then points at the handful of states that made their own.

Why an animal is not a small person here

Section 7.8 of that same document explains the mechanism, and it is not about body weight:

“Livestock and pets potentially can be exposed to higher concentrations of cyanotoxins, or have increased exposure to cyanotoxins than humans because they are known to consume cyanobacterial scum and mats and drink cyanobacteria-contaminated water”

And then the number that makes the difference concrete: “Mats and scums can represent thousand-fold to million-fold concentrations of cyanobacterial cell populations, and published microcystin concentrations have ranged up to 24 mg microcystins/L from scum material.”

A swimmer is exposed to the water column, and to a small incidental amount of it. A dog drinks the water on purpose, eats the material that has dried at the edge, and then licks the rest off its own coat. Those are three different exposures, and two of them concentrate the toxin rather than dilute it.

EPA’s 2019 document also flags a measurement problem worth carrying: “The impacts of cyanotoxins on domestic and companion animals are likely under-recognized because many cases are misdiagnosed, few cases are biochemically confirmed, and even fewer are reported in the scientific literature or to animal health systems”. So the case counts anyone quotes, including the ones on this page, are counts of what got recognised and reported.

Idaho Department of Environmental Quality states the resulting asymmetry in one sentence, and we are reproducing its comma splice as written:

“No human deaths in the United States have been caused by cyanotoxins, however, pet, livestock, and wildlife deaths caused by cyanotoxins have been reported throughout the United States and the world.”

That is a state agency saying that the fatal cases in this hazard have been animals. It is also a good illustration of why a purely human-calibrated warning system will lag the thing you actually care about.

The Word on the Sign Has No National Meaning

The most common piece of advice on this topic is to check for an advisory. The advice is fine. The problem is the next step, where a reader assumes the word carries a fixed meaning.

It does not. We opened six state frameworks on August 15, 2026 and found six vocabularies that do not map onto each other. Here is each one in its own words.

California: Caution, Warning, Danger

California’s trigger levels for posting planktonic advisory signs are published by the California Cyanobacteria and Harmful Algal Bloom Network under the state’s Water Quality Monitoring Council. Three tiers plus a no-advisory state: No Advisory, Caution (Tier 1), Warning (Tier 2) and Danger (Tier 3).

California is also the one state in this group whose posted triggers are stated to be animal-inclusive: “These trigger levels and decision tree for posting PLANKTONIC advisory signs (Caution, Warning, and Danger) were developed to protect human and animal (dogs and livestock) health from HABs.”

Note the status of the guidance, in the page’s own words: the participating agencies developed the guidelines and CCHAB “adopted them as voluntary guidance (not policy or regulation) in 2016, and recommends their use to promote consistency in public notification and risk communication throughout California.” Voluntary, and not regulation. A separate and newer set of guidelines covers benthic mats, the material that grows on the bottom and detaches, and there the page states: “The current version was approved by CCHAB Network in March 2025.” Those two dates belong to two different documents and should not be swapped.

The planktonic trigger levels, as published:

Criteria	No Advisory	Caution (Tier 1)	Warning (Tier 2)	Danger (Tier 3)
Total Microcystins	< 0.8 µg/L	0.8 µg/L	6 µg/L	20 µg/L
Anatoxin-a	Non-detect	Detected	20 µg/L	90 µg/L
Cylindrospermopsin	< 1 µg/L	1 µg/L	4 µg/L	17 µg/L
Cell Density of potential toxin producers	< 4,000 cells/mL	4,000 cells/mL	(not addressed)	(not addressed)
Site-specific indicator(s)	“No site-specific indicators present”	“Discoloration, scum, algal mats, soupy or paint-like appearance. Suspected illness”	(not addressed)	(not addressed)

The cells marked not addressed carry a dash in California’s own table rather than a number, and are not values borrowed from another tier. Two things about that last row matter for a dog. The first is that a Caution advisory can be posted on appearance or a suspected illness with no toxin number measured at all. The second is California’s own footnote to the table: “Action levels are met when one or more criteria are met.” One criterion is enough.

Kansas: Watch, Warning, Hazard

Kansas Department of Health and Environment states: “The three advisory levels are Watch, Warning and Hazard.” Its definitions, verbatim:

• Watch: “A harmful algal bloom is possible and may be present”. Its water line is “Water may be unsafe for humans and animals.” Its pet line is “Do not let people/pets eat dried algae or drink contaminated water.”
• Warning: “A harmful algal bloom is expected or present”. Its water line is “Water is unsafe for humans and animals.” Its pet line is “Do not let pets eat dried algae or drink contaminated water.”
• Hazard: “A harmful algal bloom is present, and extreme conditions exist”. At this level KDHE states “It is recommended that either a portion of the lake or the entire lake or zone, be closed to the public.”

Kansas also publishes a general animal instruction that covers working dogs by name: “Exposure to HABs, whether through contact or ingestion, can cause illness and even death in animals and humans. Do not allow livestock, pets, or working animals such as hunting dogs to drink from HAB-affected waters, eat dried scum on shorelines, or lick their fur after exposure.”

Utah: Warning Advisory, Danger Advisory

Utah has only two levels, and the word Warning is the lower of them. Utah Department of Environmental Quality’s guidance table pairs each with an action and an outcome:

Utah tier	What to do	What Utah says can happen
Warning Advisory	“Avoid primary contact recreation (e.g., swimming, waterskiing, wading)”	“Under a Warning Advisory there is potential for short-term effects (e.g., rash, nausea, vomiting, diarrhea) or long-term illness”
Danger Advisory	“Stay away from the waterbody”	“Under a Danger Advisory there is potential for short-term effects, long-term illness, or death”

We searched Utah’s guidance page for pet and animal content on August 15, 2026 and found exactly one occurrence, and it is not an instruction to owners. It is a trigger for the health department: “If a LHD receives reports of human or animal illness or death that is plausibly linked to cyanobacteria, an immediate public health advisory is recommended.” So in Utah, a sick animal is an input to the advisory system rather than an audience for it. That is a real and useful thing to know, and it is a description of that one page rather than of everything Utah publishes.

Oregon: Advisory, Precaution, Lifted

Oregon inverts the ranking that California and Kansas use. Here, Advisory is the top tier. From Oregon’s advisories page:

“Advisory: Cyanotoxin levels have been confirmed through testing to be unsafe for swimming and boating at speeds that cause water to spray into your face, OR a combination of conditions indicate that cyanotoxin levels may be unsafe for these activities. Toxin levels are unsafe for pets.”

“Precaution : A bloom has been confirmed or cyanotoxins are present but at levels that are safe for human recreation. Toxins levels may still be unsafe for pets.”

The plural in “Toxins levels” is Oregon’s, and we have left it. What matters is the structure of that second definition. Precaution is defined as human-safe, and the pet line is defined as an open question. Oregon is telling you, in the tier definition itself, that the two answers have come apart.

Oregon adds a third state, and a downgrade: “Advisory downgraded to precaution : An ’advisory ’ is downgraded to a ‘precaution’ when wat er testing shows s afe level s for human recreation, but a bloom or toxins are still present. Toxin levels may still be unsafe for pets.” The broken spacing there is an artifact of how the page renders, and the substance is clear enough: the downgrade is triggered by the human number.

Read the fourth definition on that same page next to a sentence in Oregon’s own guidelines. The advisories page states: “Precaution lifted : A ‘precaution’ is lifted when testing shows cyanotoxins are not present, or when the bloom is visibly gone.” The guidelines state: “It is possible therefore, for visual observations to indicate that a bloom has disappeared and still have toxins present.”

Putting those two sentences together is this page’s reasoning, not a claim Oregon makes: one of the two routes out of a Precaution is visual, and Oregon’s own guidelines document says a visual all-clear does not establish that the toxins are gone. That does not make a lifted precaution meaningless. It means a lifted status can rest on the bloom no longer being visible, which is the one form of evidence the guidelines say can be wrong about toxins.

Wyoming: Under Investigation, Bloom Advisory, Toxin Advisory

Wyoming Department of Environmental Quality uses three statuses, and it is the only one of the six that separates a bloom is present from toxins were measured:

“As summarized in Wyoming’s HCB Response Strategy, when a HCB is reported on a waterbody without a current recreational use advisory and the report is determined to be credible, the waterbody will be identified as “Under Investigation””

That sentence runs straight on into the name of Wyoming’s story map on the page itself, with no punctuation between them, which is how the link label renders inside the sentence. The next step is its own sentence: “If the Department of Environmental Quality (DEQ) verifies that a HCB is present at the waterbody, the Wyoming Department of Health (WDH) will issue a BLOOM ADVISORY.”

Then: “If cyanobacteria abundance or cyanotoxin concentrations are above public health thresholds, the WDH will retain the BLOOM ADVISORY, issue a new BLOOM ADIVSORY if one has not been issued, or issue a TOXIN ADVISORY.” The misspelling of ADIVSORY there is Wyoming’s own, and we have reproduced it rather than tidy a quotation.

Wyoming also publishes two caveats about its own list that almost no other state states so plainly:

“Keep in mind that there may be waterbodies with HCBs that the Wyoming Department of Health is not aware of. Also, keep in mind that waterbodies with an advisory are not closed since HCBs may only be present in certain areas and conditions can change frequently.”

Idaho: Health Watch, Health Alert, Health Advisory

Idaho’s three levels produce the sharpest inversion in this group. Idaho Department of Environmental Quality describes the framework this way: it “includes two risk levels— Health Watch and Health Alert —that provide timely public information while toxin test results are pending. Health Advisories are issued as a press release through the DHW News webpage to inform news outlets and the public of where an active, toxic bloom has been confirmed.”

Now read the middle tier and the top tier against each other:

• Health Alert (middle): “Indicates a high level risk to the health of pets and livestock, and can cause illness in humans, especially if exposure is prolonged or continual.”
• Health Advisory (top): “Indicates a high level of confirmed risk to humans from harmful algal blooms.”

The tier that names your dog first is the middle one. The top tier, the one that gets a press release, is described in human terms. Both of them carry the same animal instruction in their action lists, “allow animals in the water” appearing under DO NOT for each, and the lowest tier softens it to USE CAUTION: “Allowing animals in the water; wading; swimming; kayaking, paddleboarding, etc.; eating fish from the water”.

The six side by side

Every cell below is what that state’s own page states, read on August 15, 2026. Where a state does not address something, the cell says so rather than borrowing an answer from a neighbouring row.

State (read 2026-08-15)	Tier names, lowest to highest	Where “Warning” sits	Where “Advisory” sits	Does a tier definition mention pets?
California	Caution (Tier 1), Warning (Tier 2), Danger (Tier 3)	Middle of three	Not a tier name	The trigger levels are stated to be “developed to protect human and animal (dogs and livestock) health”
Kansas	Watch, Warning, Hazard	Middle of three	Not a tier name	Yes, Watch and Warning each carry a pets line
Utah	Warning Advisory, Danger Advisory	Lower of two	In both tier names	Not addressed in the tier definitions; animals appear only as a trigger for issuing an advisory
Oregon	Precaution, Advisory (plus Lifted)	Not a tier name	Highest tier	Yes, and separately from the human line, in the Advisory, Precaution and downgrade definitions; the Precaution-lifted definition carries none
Wyoming	Under Investigation, Bloom Advisory, Toxin Advisory	Not a tier name	In two of three tier names	Not in the tier definitions; the pets and livestock instruction sits in the general guidance
Idaho	Health Watch, Health Alert, Health Advisory	Not a tier name	Highest tier name	Yes, and the middle tier is the one that names pets and livestock first

This is the site’s own conclusion from the six rows above, not a statement any of these agencies makes: the word on a sign is not information until you have read that state’s definition of it. Six states, six vocabularies, and the two words a traveller is most likely to think they understand, Warning and Advisory, rank in opposite directions depending on which side of a state line the lake sits on. Read the definition, not the word.

A Worked Example, on One State’s Live Table

Abstractions about tiers are easy to nod at and hard to act on, so here is the same point as arithmetic on a page anyone can open.

On August 15, 2026 we read Oregon’s Blue-Green Algae Advisories page and counted every row in its current advisory table. The results, with the denominator attached:

• 34 waterbody rows listed in total.
• 23 at Precaution, which Oregon defines as “levels that are safe for human recreation. Toxins levels may still be unsafe for pets.”
• 8 at Advisory, 2 at Precaution Lifted, 1 at Permanent Advisory.
• Of the 23 Precaution rows, 15 carried a numeric toxin measurement, 3 read Non-detect, and 5 had no measurement shown.
• Of those 15 numeric Precaution rows, 12 were above at least one of Oregon’s own dog-specific values.

Those twelve, with the figures Oregon’s table published: Willamette River at Portland, microcystin 0.22; Wapato Marsh at Oaks Bottom, 0.26; North Fork Santiam River, 0.3; Siltcoos Lake, 0.37; Brownlee Reservoir Powder Arm, 0.58; Detroit Reservoir, 0.73; Cold Springs Reservoir, 1.08; Lake Billy Chinook, 1.09 (the unit is omitted in that cell); South Tenmile Lake, 2.53; Cullaby Lake, 3.86; plus Clackamas Cove at saxitoxin 0.15 and Hyatt Lake at anatoxin-a 0.54. Oregon’s dog values are 0.2 for microcystin, 0.02 for saxitoxin and 0.4 for anatoxin-a.

The three numeric Precaution rows below every dog value were Fern Ridge Reservoir at 0.17, Devils Lake at 0.18 and Ochoco Reservoir at 0.15. So the comparison is not one-sided, and the milder status is sometimes genuinely mild for a dog too. It is simply not what the status is telling you.

The comparison in the two paragraphs above is ours, not Oregon’s. Oregon publishes the advisory table and Oregon publishes the dog values, in two different documents, and states that the dog values are not used to issue advisories. Putting the two together is this page’s own arithmetic. It is arithmetic anyone can repeat, and Oregon’s own guidelines describe the dog values as being “offered as a resource to veterinarians and veterinary associations to use as appropriate, when treating dogs believed to have been exposed to cyanotoxins.” That is close to what we are doing with them here.

One more thing we found on that page, and it is worth knowing about any state page you rely on. At the top, on the day we read it, sat this notice: “This webpage will not be updated August 8 - 18, 2026. For up-to-date information on cyanoHAB advisories, view the advisory map or call 1-877-290-6767.” A ten-day gap in the table, in the middle of bloom season, with a pointer to the map instead. A state advisory page is a snapshot maintained by people with other work, not a live feed, and it will sometimes say so if you read the top of it.

The States That Do Publish a Dog Number, and What Theirs Actually Cover

EPA’s State & Tribal Toxin Thresholds page, last updated July 13, 2026, is a compilation of the thresholds states use for advisory decisions. Buried in a table dominated by drinking-water and recreation rows are four rows about animals. They are worth reading closely, because each one is narrower than it first appears.

Oregon: informational, not operational

EPA’s compilation lists an Oregon row labelled Dog Information Values: anatoxin-a 0.4, cylindrospermopsin 0.4, microcystin 0.2, saxitoxin 0.02 micrograms per liter, citing Oregon’s Advisory Guidelines. We retrieved that Oregon document directly and confirmed the figures in Table C-4, alongside the human values in Table 2 of 15, 15, 8 and 8 respectively.

Oregon’s own note on how those values were derived is short and worth including because it explains why a dog number is not simply a scaled human number: “These dog-specific RUVs are consistent with California EPA’s estimate of the amount of water an exercising dog consumes per kilogram body weight (from 0.168 to 0.255 L/kg-day). The dog-specific value for saxitoxins was further modified by application of an uncertainty factor to the dog-specific TDI for interspecies differences in sensitivity between humans (the species in the critical study) and dogs.”

Oregon also draws a practical consequence for drinking water that most owners would not guess, and we are reproducing the sentence including its own grammatical slip:

“Note: Pet owners should be aware that the RUVs for dogs is below the GVs for drinking water affected by cyanotoxins. Because of this, OHA recommends owners supply their pets with bottled water or water from alternative sources when a drinking water advisory is in place.”

That is a state health authority saying that during a drinking water cyanotoxin advisory, the tap standard is not calibrated to the dog either.

Indiana: real thresholds, one dog park

EPA’s compilation lists two Indiana rows, Dog Recreation Advisory Value and Dog Recreation Prohibited Value. We went to the Indiana Department of Environmental Management page EPA cites, dated August 14, 2026, and found the table published in full:

Exposure Reference Values, µg/L	Microcystin	Cylindrospermopsin	Anatoxin-a	Saxitoxin
Human Recreation Advisory	8	6	8	0.8
Dog Recreation Advisory	0.4	0.5	(not published)	(not published)
Dog Recreation Prohibited	0.8	1.0	0.4	0.05

Indiana’s human advisory value for microcystin is 8 and its dog advisory value is 0.4, a factor of twenty on the state’s own page, in one table, with no interpretation needed from us.

Now the qualifier, which is the sentence that would be easiest to leave off and is the most important one in the section: “A warning or closure will be issued to dog owners using the Fort Harrison State Dog Park when cyanotoxins are detected above the levels in the table below.”

That is one dog park. Indiana did not derive those dog numbers itself, and its own page says where they came from: “For cyanotoxin exposure for dogs, the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment has developed action levels for microcystin, anatoxin-a and cylindrospermopsin. The Oregon Health Authority Public Health Division has set an action level for saxitoxin.” So Indiana adopted two other states’ work and applies it operationally at a single named location. Everywhere else in the state, the sampling programme is doing something else, and Indiana says what: “Although our test results are specifically for the beach where pets are not permitted to swim, please keep pets out of the water along shallow banks and the shoreline.”

Read that twice. The tested water is a swimming beach where dogs are not allowed, and the state is separately asking you to keep the dog off the shallow banks and shoreline, which is water nobody tested. That is not an oversight on Indiana’s part; it is an honest description of what a beach monitoring programme covers.

California and the other end of the scale

California derived dog action levels too, and they look wildly different from Oregon’s, which is a trap worth defusing rather than a contradiction. EPA’s 2019 criteria document, section 7.8.1, describes California’s 2012 work: the state calculated “an acute (lethal) and a subchronic scenario” and arrived at “acute action level of 100 μg/L for microcystins and 200 μg/L for cylindrospermopsin”, with subchronic canine water values of 2 and 10 in Appendix H.

So California’s acute canine figure is 100 and Oregon’s dog figure is 0.2, and both are about dogs. They are not measuring the same thing, and EPA’s own text is what separates them. California’s number came from dividing a domestic-animal reference dose by an intake estimate, and EPA describes the result as “a cyanotoxin concentration that would result in exposure at the RfD level or below”. Appendix H then attaches the exposure window: “Acute refers to exposures in a single day” and “Subchronic refers to exposures over multiple days”, and Appendix H gives California a subchronic canine water value of 2 for microcystin against that acute 100. Oregon’s 0.2 is not an exposure-duration figure at all; it is the value Oregon publishes to educate owners and hands to veterinarians. This is the site’s own reading of the two documents, not a statement either state makes: a single-day action level and an owner-education value answer different questions, and neither document presents its number as a line below which a dog is safe. A page that put those two numbers side by side without saying which question each answers would make a state look reckless, and none of them is.

Everyone else

EPA’s 2019 document is blunt about how short this list is: “Other states mention animal poisoning in their guideline documents but do not give guideline values specific to livestock or companion animals.” It gives Ohio as the example of a state that includes pets in its advisory without a pet-specific number, and we are quoting EPA’s characterisation rather than Ohio’s own words, because we could not land an Ohio response document during this work:

“Ohio includes pets in their public health advisory at threshold levels of 6 μg/L for microcystin and 5 μg/L for cylindrospermopsin; however, Ohio issues the disclaimer that thresholds used are protective of human exposure and may or may not be protective of animals such as dogs or livestock (Ohio EPA 2016).”

Those are EPA’s words in 2019 about an Ohio document from 2016, and Ohio’s current programme may differ. We flag it because that disclaimer, if Ohio still publishes it, is this entire page in one sentence, written by a state about its own numbers.

One more from the same section, which we include with its own weakness attached: EPA reports that at Presque Isle State Park in Pennsylvania, where monitoring covers locations including designated dog beaches, “Warning signs are posted specifically for dog owners when microcystin levels are detected above 0.2 μg/L”. EPA’s citation for that is two personal communications from 2017, which is a thin sourcing basis for a durable claim, and 2017 is a long time ago for a monitoring programme. Treat it as an example that dog-specific posting has been done somewhere, not as a current description of that park.

The Four Things the Advisory System Cannot See

If the advisory is calibrated to people, what is left uncovered? Four things. The first three are stated by agencies about their own programmes. The fourth is what we found when we went looking on August 15, 2026, and it is scoped to the pages we opened.

1. A great deal of water is never sampled

Idaho: “Due to the large number of waterbodies across Idaho, DEQ cannot continuously monitor every waterbody at all times. HABs can develop quickly, particularly in hot weather. When in doubt, stay out of the water.”

Kansas describes a programme that is entirely reactive: “KDHE samples public use lakes only in response to complaints of human or animal illness or visual sighting of possible blue-green algae by the public or by lake managers or agency scientists.” Under that model, the first sick animal is part of the detection system.

Wyoming states the limit as a caution to the reader: “Keep in mind that there may be waterbodies with HCBs that the Wyoming Department of Health is not aware of.”

And for private water, Wyoming states the scope directly: “The Department of Environmental Quality’s (DEQ) Harmful Cyanobacteria (HCB) Program focuses on publicly accessible waterbodies used for full-body contact water recreation.” Your neighbour’s pond is outside every programme on this page.

2. The tested spot is not the dog’s spot

This is the one almost nobody thinks about, and two sources make it concrete from opposite directions.

EPA describes where the material goes: “Wind-driven currents may cause blooms to amass on shorelines. These accumulations are much larger than blooms in open waters, thus presenting a greater risk to human and animal health.”

Indiana describes where the sample comes from: “Although our test results are specifically for the beach where pets are not permitted to swim, please keep pets out of the water along shallow banks and the shoreline.”

Putting those two together is this page’s reasoning, not a claim either source makes: the wind concentrates bloom material at the shoreline, the shoreline is where a dog wades, drinks and scavenges, and the monitoring sample is frequently drawn from a designated swimming area that the dog is not in. The number on the sign and the water around your dog’s feet are not necessarily samples of the same thing.

3. The satellite cannot see the shallows either

EPA runs a freshwater cyanoHAB forecast model on lakes measured by the Cyanobacteria Assessment Network, CyAN. It is genuinely impressive and it is not a substitute here. EPA describes the model’s coverage as “over 2,000 of the largest U.S. lakes and reservoirs across the lower 48 states”, with a stated “overall prediction accuracy of 90 percent”, and attaches a caution: “Note that the forecast is not meant to replace regular sampling or observation, but to help inform those monitoring efforts.”

Then the resolution caveat, in EPA’s own words:

“As shown in Figure 1, the CyAN satellite generally does not resolve (“accurately see”) shallow areas along the edge of the lake, small embayments, narrow areas of the lake/reservoir, etc. This means lakes where blooms may be isolated or occur in small specific embayments may not register as having a high probability of a bloom at the scale of all the resolvable portions of the lake.”

EPA’s application page adds the size floor: the app covers “water bodies that are roughly one square kilometer or greater.”

Again, the join is ours: the shoreline edge, the small embayment and the pond under a square kilometre are precisely the three places a dog is most likely to be in the water, and they are the three the national satellite product is documented as being weakest at or blind to. CyAN is a tool for water managers scanning large lakes, and EPA presents it as exactly that.

4. No federal page we opened publishes live per-lake advisory status

We opened five federal pages on August 15, 2026 looking for a national live lookup: EPA’s HAB Advisories page, its HAB Forecasts page, its CyAN application page, and both State and Tribal pages. None of them publishes the current advisory status of a named waterbody, and each routes to state programmes for it.

The closest is EPA’s HAB Advisories page, which states that EPA “compiles and displays recreational and drinking HAB occurrence and/or advisory data publicly reported by states on a monthly basis” and that the result is “summarized at the national level and presented in a monthly time lapse map and bar graph to help inform spatial and temporal changes in HAB occurrence and/or advisory reporting in the United States.” A monthly national time-lapse is a useful research product and it is not a lookup for Saturday’s trip to the lake.

That paragraph describes what those five pages contained on that date. It is not a claim that no such tool exists anywhere.

Where the Dog Actually Gets Exposed

The routes are published, and they are broader than swimming.

EPA’s exposure page lists five: “Pets and other animals can be exposed to HAB toxins through drinking toxin-contaminated water, swimming in waters with a HAB, eating HAB mats, eating contaminated animals (e.g., fish or shellfish), or by licking toxins off their fur or hair.”

Oregon’s guidelines put the same thing in behavioural terms: “Animals are extremely sensitive to cyanotoxins when present and can become very ill or potentially die due to exposure at very low levels. The primary route of exposure to these toxins is through ingestion. Ingestion occurs when pets and wildlife drink water from a cyanobacteria-filled lake or pond, lick their fur after swimming, or eat dried cells that accumulate along the shoreline.”

California adds why a dog is drawn to it rather than repelled: “Animals are attracted to the taste and smell of HABs. Dogs lick algae caught in their coat after being in the water. Dogs that scavenge around the shore may ingest drying clumps of algae.” Indiana’s environmental agency adds the grooming mechanism: “Dogs are particularly susceptible to blue-green algae poisoning because the scum can attach to their coats and be swallowed during self-cleaning.”

California’s water quality portal lists two further routes for dogs that no other source here covers:

• “Skin contact or ingestion at any affected water body including lakes, rivers, streams, or ponds, as well as residential ponds or pools.”
• “Ingestion of blue-green algae health supplements.”

That second one is worth pausing on. California’s 2018 dog owner factsheet phrases it as exposure “By ingesting health supplements containing blue-green algae, which may unintentionally include HAB toxins.” Blue-green algae is sold as a supplement ingredient, including in products marketed for animals, and this is a state agency naming that as an exposure route. We are not going to extend that into a recommendation about any specific product, because that is not what the source says and we have tested nothing.

California also lists “Inhalation of airborne droplets or mist containing algal material and/or cyanotoxins” among dog exposure routes for freshwater blooms.

It is not only dogs

California’s portal states: “All domestic animals are at risk for freshwater HAB-related illnesses following contact with a potentially HAB-impacted water body.” On large animals it reports: “HAB-related illnesses have been reported in cattle, horses, sheep, pigs, chickens, and turkeys”, and “Most illnesses were fatal and associated with visible HAB material, including scum and algal mats.” It adds a route that has nothing to do with a waterbody at all: “Livestock may also be exposed to HAB-related toxins through eating feed products that contain blue-green algae.”

For livestock water generally, California’s guidance is: “Livestock water supplies should be checked for HABs frequently throughout the year. Treat all HABs as potentially toxic to livestock, and prevent animals from accessing water bodies with visible HABs (scums, discolored water, or mats).” EPA’s compilation records an Oregon livestock watering value for microcystin as well, under the abbreviation LW, which EPA defines on the same page as Livestock Watering.

We did not find cat-specific cyanotoxin guidance in the agency sources we opened for this page. That is a description of our search, not a finding that none exists.

Looking at the Water Is Not a Test

The identification advice on this hazard is genuinely useful and genuinely insufficient, and both halves need saying.

EPA’s dog page gives three signs to react to: “It’s slimy or looks like foam, scum or mats on the surface of the water.” / “The color is weird. Harmful algal blooms can be blue, bright green, brown or red and may look like paint floating on the water.” / “It stinks. Some (but not all) harmful algae produce a nauseating smell.” Note EPA’s own hedge in that third one.

Indiana’s Board of Animal Health publishes a hands-on distinction: “Blue-green algae is not the type that grows in mats of plant material along shorelines. When you pick it up, the algae disperses in the water and does not hang together in a stringy mass.” Useful for telling a cyanobacterial bloom from harmless filamentous algae. Note that it describes the floating, water-column form, and that California maintains an entirely separate set of guidance for benthic cyanobacteria. California’s response guidance describes those as mats “attached to the bottom, floating, or stranded along the shore”, which is a different appearance from a water-column bloom and, on this page’s own reasoning rather than California’s statement, is stranded material at exactly the place a dog scavenges.

Now the limit. EPA states: “You cannot tell if a bloom is harmful by looking at it, so it is best to use caution and stay away.”

And the case that proves the reverse failure is Oregon’s own, recorded in its May 2024 guidelines:

“Between August 21 and August 30, 2009, four dogs died of acute anatoxin-a poisoning shortly after drinking water from Elk Creek and the Umpqua River near the confluence of these two streams at Elkton, Oregon.”

The next sentences publish the sampling, and we are quoting the numbers rather than summarising them, because they qualify how far this case reaches. The document records that samples collected from the area on September 1, 2009 had no detectable toxigenic cyanobacteria, and then states: “However, other samples collected from the same areas on the same day revealed detectable levels of anatoxin-a (0.5 µg/L). Microcystin was measured at an average concentration of 15 µg/L (1.5 times above the advisory threshold at the time of 10 µg/L).”

Two qualifiers on that, and reading them out is ours rather than Oregon’s: those September 1 samples were above the advisory threshold Oregon used at the time, so this is not a case where every number said the water was fine; and the deaths had already happened between August 21 and August 30, before any of that sampling was done. The 10 µg/L in Oregon’s sentence is the threshold that was in force in 2009 and it is not Oregon’s figure now. The guidelines quoted at the top of this page set 8 for people and 0.2 for dogs.

What the case does establish is what Oregon says next: “There was no visible bloom or scum reported in that area of the creek when these fatalities occurred. This case demonstrates that lethal concentrations of cyanotoxins can be present in the absence of detectable toxigenic cyanobacterial cells.” Oregon then states what it did about that uncertainty, in its own words: “Due to the uncertainty associated with cell densities, level of toxin production and exposure to people and pets, OHA has removed cell count data from the advisory issuing and lifting protocol.”

Oregon’s guidelines add the tail end of the same problem: “Cyanobacteria can release their toxins during bloom formation and as the bloom is declining. Cyanotoxins, like microcystin and cylindrospermopsin can take some time to degrade even after a bloom has dispersed. It is possible therefore, for visual observations to indicate that a bloom has disappeared and still have toxins present.”

So visible scum is a reason to leave. Clear water is not a reason to stay. Those are not symmetrical, and treating them as if they were is the mistake this section exists to prevent.

Treatment Is Not the Answer Here, and Two States Say So

This site has pages about making questionable water safe for an animal: our tablets versus filter comparison and our dog water filter guide. Those pages are about pathogens: bacteria, viruses, protozoa like giardia and cryptosporidium, and the leptospirosis risk that comes with stagnant water. A cyanotoxin is a different kind of hazard and the methods do not carry over, and both of those pages now carry that carve-out in their own words.

The two clearest statements come from state environmental agencies.

Idaho Department of Environmental Quality: “Effects can be more serious in animals since they are more likely to drink the water, lick toxic cyanobacteria from their fur, or eat toxic mats. Boiling water does not remove cyanotoxins and will concentrate the toxins. Most portable drinking water filtration products (like those used for backpacking) are not effective at removing cyanotoxins.”

Wyoming Department of Environmental Quality: “Do not ingest water from the bloom. Boiling, filtration and/or other treatments will not remove toxins.”

Two details matter. Boiling does not merely fail; Idaho says it concentrates the toxins, which makes it an active mistake rather than a wasted effort. And Idaho’s hedge is the word Most, which we are keeping: Idaho does not say that no filtration product on earth touches cyanotoxins, and neither do we.

The following is this page’s own reasoning rather than something any of these sources states in this form: the reason the methods do not transfer is that they target the wrong kind of thing. A filter strains organisms out by size and boiling kills them with heat, but a cyanotoxin is a chemical already dissolved in the water. Killing the cyanobacterium that produced it does not remove what it released, and rupturing the cell can put more of it into the water. That is why the correct move at a bloom is not harder treatment. It is a different water source.

Indiana’s Board of Animal Health makes the same mechanism explicit for pond owners: “Do not treat blooms with algaecides or herbicides as they break open the bacteria cells. This will lead to a rapid release of toxins in the water.”

We should flag, rather than smooth over, that the same Indiana page also lists among prevention methods “restricting access to infested ponds and treatment of the pond using copper sulfate or algaecides”, and adds “Be sure to check the product manufacturer’s safety precautions before allowing animals access to the water” and “Livestock should be fenced away from the pond for several days after the treatment is complete.” Those two passages pull in different directions on chemical treatment. We are reporting both as the page carries them rather than picking the one we prefer, and if you are deciding whether to treat a pond your animals drink from, that is a question for your veterinarian or your state extension service rather than for us.

For a household water advisory, which is a different situation from a lake, our page on what a boil water advisory actually tells you to do for pets works through the advisory types and where boiling is and is not the answer, including the case where an agency tells you not to boil. And Oregon’s note above applies directly to a drinking-water cyanotoxin advisory: it recommends “owners supply their pets with bottled water or water from alternative sources when a drinking water advisory is in place.”

What To Do When There Is No Number At All

This is the situation many readers are in. Three states say in their own words that they cannot sample everything, and eighteen of the fifty-one state-level entries in EPA’s threshold compilation carry no recreation threshold at all. It has an answer, and three agencies publish the same one.

EPA: “When in doubt, stay out! If you see signs of a bloom, stay out of the water and keep your pets out of the water.”

Idaho: “When in doubt, stay out of the water.”

Oregon’s FAQ turns it into a set of habits, and we are reproducing its own slip of grammar in the second one:

• “Stay out of the water in or around a bloom. Be sure to keep children and pets away.”
• “Never drink or cook with affected water, and do not let your pet to drink water from the area.”
• “Although toxins are not absorbed through the skin, it’s still a good idea to wash off if you or your pet come in contact with a bloom. Wash your skin or your pet thoroughly with a clean source of water and soap if available.”

That third one contains a distinction worth holding onto: Oregon states that “Cyanotoxins are not absorbed through the skin. However, a red, raised rash can develop after contact with a bloom.” Skin contact is not the main danger. Skin contact followed by grooming is, which is why the rinse matters so much for an animal and comparatively less for you.

Wyoming’s version pairs the rinse with the phone call: “If people, pets, or livestock come into contact with a bloom, rinse off with clean water as soon as possible and contact a doctor or veterinarian.”

The practical version, for a lake you cannot get information about: bring the animal’s water with you so the lake is never the drinking source, keep it off the shoreline where dried material accumulates, rinse it before it has a chance to groom, and treat any unexpected illness in the next few days as a veterinary call rather than a wait-and-see.

Rinsing, Symptoms, and the Vet Call

The agencies below publish rinse instructions and they do not fully agree, so here they are separately rather than merged. Wyoming publishes one of its own, quoted earlier on this page.

Idaho’s is in the table below, and it also names who to call. We are reproducing its broken second sentence exactly as Idaho publishes it: “If you, your kids, or your pets come into contact with water that you think might have a harmful algal bloom, it’s important to rinse right away with soap and clean water. If someone is experiencing symptoms of cyanobacteria exposure, and check with your healthcare provider or veterinarian for treatment. In the case of an emergency, call 9-1-1.”

Source (read 2026-08-15)	What it says to rinse with	Protection for the person	Explicit do-not-lick instruction
US EPA, How to Protect Your Pooch	“give your dog a thorough rinse in clean, fresh water”	“Wear gloves to protect yourself”	Not stated on this page
US EPA, exposure page	“rinse them with tap water as soon as possible”	Not addressed	“don’t let your pet lick their fur after swimming in contaminated water”
Indiana Dept. of Environmental Management	“rinse them off with soap and water immediately to remove the toxin”	Not addressed	“Do not let them lick the algae off their fur.”
Idaho Dept. of Environmental Quality	“rinse right away with soap and clean water”	Not addressed	Not stated in this passage
Oregon Health Authority	“Wash your skin or your pet thoroughly with a clean source of water and soap if available”	Not addressed	Not stated in this passage
California Water Quality Monitoring Council	“Wash your pets with clean water after lake or river play. Provide clean drinking water.”	Not addressed	Not stated in this passage
California OEHHA, 2018 dog owner factsheet	“Always wash your pets with clean water after water contact.”	Not addressed	Not stated; it states “Never let your dog eat scum or algae.”

Only EPA’s dog page mentions gloves. That is worth acting on even though only one source states it, and this next sentence is the site’s own reasoning: if the material on the coat is dangerous enough that the animal must not lick it, then it is on your hands while you are scrubbing it off, and the one agency that thought about the person doing the rinsing said to wear gloves.

Not one of those instructions names the lake as the rinse source, and the next join is the site’s own reasoning rather than an agency’s: EPA names clean, fresh water and tap water, Oregon names a clean source of water and soap, Indiana and Idaho name soap and water, and California names clean water. At a boat ramp or a rural shoreline there is no tap, and a thorough rinse of a wet coat is a great deal more water than the bottle you packed for the animal to drink, so carry rinse water in addition to its drinking water. Do not rinse the animal in the waterbody you are trying to get off it. If you have no clean rinse water with you, the interim action is to stop the grooming until you reach some, which is the step EPA and Indiana each publish separately.

On timing and symptoms, three sources with overlapping lists:

EPA’s exposure page: “Symptoms of exposure to HABs in pets can include excessive salivation, fatigue, difficulty breathing, vomiting, diarrhea, and seizures. Death can occur within hours to days of exposure.”

EPA’s dog page: “Symptoms can arise anywhere from 15 minutes to several days after exposure. Take pets to the vet immediately if they suffer from: Diarrhea or vomiting / Weakness or staggering / Drooling, difficulty breathing or convulsions.”

Indiana’s Board of Animal Health, on the window: “Contact a veterinarian immediately. Animals may die within minutes of clinical signs appearing, but can survive for several hours or up to two or more days after exposed.” And on what treatment can and cannot do: “If the animal has consumed a lethal dose, no antidote exists for the toxins. Sometimes, animals are found dead with no signs observed.”

California’s list is the longest, and its last item is the one to actually carry, because it does not require you to match anything: contact a veterinarian for loss of energy, loss of appetite, vomiting, stumbling and falling, foaming at the mouth, diarrhea, convulsions, excessive drooling, tremors and seizures, dermal irritation or rash, or “Any unexpected sickness that occurs within a day or so after being in contact with water.”

One thing to say on the phone. California’s water quality portal states: “Doctors and veterinarians may not be familiar with the symptoms of cyanotoxin exposure, potential treatment, and how to report potential HAB-related illnesses in humans, pets, and livestock.” So name the exposure. Say the animal was in a lake, pond or river, say whether there was visible scum, and say when. California maintains a fact sheet for veterinarians on this specific exposure, and so does Vermont, and a practice that has not seen a case can be pointed at them.

This page publishes no treatment and no dose. If your animal is symptomatic, the destination is a veterinary practice, and the useful thing you can do is get there quickly with an accurate exposure history.

Reporting is part of the system

In several states the reporting form is not a formality; it is how the next family finds out. Kansas samples in response to complaints. Oregon’s advisories page carries three separate reporting forms, one of which is an Animal Illness Reporting Form. Wyoming asks that human or animal illness be reported to its Department of Health. Indiana’s Board of Animal Health runs a surveillance programme and states: “Veterinarians are asked to report incidents of blue-green algae exposure in animals.” California’s response guidance treats an animal illness report as a trigger for interagency follow-up, and EPA’s dog page ends with “Report the bloom to your state’s health department.”

If your animal gets sick after a lake trip, filing the report is the part that changes what is posted at that lake next week.

Finding Your State’s Page

EPA publishes a national directory of state programmes. It is called State & Tribal HAB Programs and Resources, its footer records a last update of July 15, 2026, and it is the right starting point.

It is a link directory rather than a dashboard, and it is worth knowing its shape before you rely on it. We parsed the page’s raw HTML on August 15, 2026 and then checked every link in it. What we found:

• 51 state-level sections, covering all 50 states and the District of Columbia.
• 135 links in total, ranging from 1 entry (ten jurisdictions: Alabama, Alaska, the District of Columbia, Kansas, Michigan, New Hampshire, New Mexico, South Dakota, Tennessee and Wyoming) to 9 (New Jersey).
• No entries for any US territory. We searched the page body for Puerto Rico, Guam, the US Virgin Islands, American Samoa, the Northern Mariana Islands and the word Territor, and found none of them.
• No tribal programme entries in the alphabetical listing, despite the page’s title. The word Tribal appears on the page only in its title, metadata and navigation. EPA does list Tribal entries on a different page, its State & Tribal Toxin Thresholds compilation, where six appear: the Hoopa Valley Tribe, the Miccosukee Tribe, the Northern Cheyenne Tribe, the Pueblo of Sandia, Santa Clara Pueblo, and the Confederated Tribes of the Coos, Lower Umpqua, and Siuslaw Indians. If you are looking for a tribal programme, that is the page to open.
• Of the 135 links, 126 resolved for us, 3 returned 404, and 6 returned 403. A 403 is a block on our end and is not evidence that a page is gone; those six are Arizona’s environmental quality entry, both Massachusetts entries, New Hampshire, New York’s environmental conservation entry, and the Clemson factsheet under South Carolina.
• The three 404s we confirmed by reading the page that came back, not by the status code alone. Both Missouri Department of Health and Senior Services entries serve a page headed “Page not found | Missouri Department of Health and Senior Services”, which leaves Missouri’s Department of Natural Resources entry as its only working link in the federal directory. New Jersey’s Montclair State University entry serves “Page Not Found - Montclair State University”; New Jersey’s other eight entries all resolved.
• Titles and destinations do not always match. The clearest case: an entry under Connecticut titled for interim guidance to local health departments links to cdphe.colorado.gov, the Colorado health department, which is the identical URL EPA also uses under Colorado. Three more entries are credited to one agency and link to another: two Indiana entries credited to the Department of Environmental Management link to the Indiana State Board of Animal Health; an Illinois entry credited to the Department of Public Health links to the Illinois EPA; a Maryland entry credited to the Department of Natural Resources links to the Department of the Environment.
• Some entries are not agency pages at all. Utah’s section includes a commercial testing laboratory. Several entries land on department front pages or general alerts pages rather than on algae content.

None of this makes the directory a bad resource. It makes it a directory of fifty independent programmes that change their websites on their own schedules, which is exactly what it is. Our own links will rot the same way, which is why the table below records what we found and when, rather than pretending it is permanent.

The routing table

Every entry title and URL below is taken verbatim from EPA’s State & Tribal HAB Programs and Resources page as parsed on August 15, 2026. Nothing has been reworded, merged, or dropped, including the entries whose titles and destinations disagree, because hiding those would be hiding the thing you most need to know before you click. The final column reports what our own link check returned on that date, plus anything we noticed about a title and its destination.

One row per state, and no state is treated as a minor one. A state with a single entry gets the same treatment as a state with ten.

State	What EPA’s directory lists, with every entry linked	Entries	What we found on 2026-08-15
Alabama	Alabama Department of Environmental Management, ADEM/ADPH Coastal Alabama Beach Monitoring Program	1	The single entry resolved for us.
Alaska	Alaska Harmful Algal Bloom Network (AHAB)	1	The single entry resolved for us.
Arizona	Arizona Harmful Algal Blooms, Arizona Department of Environmental Quality Arizona Water Watch Arizona Department of Health Services - Harmful Algal Blooms	3	2 of 3 resolved for us. 1 returned 403 to our request, which is a block on our end and not evidence the page is gone.
Arkansas	Arkansas Department of Environmental Quality, Online Harmful Algae Bloom Complaint Reporting Form Arkansas Water Resources Center, Algal Blooms in Arkansas Streams, Ponds, and Lakes (pdf) Arkansas Department of Environmental Quality - Harmful Algal Blooms	3	All 3 entries resolved for us.
California	California HAB Portal California Office of Environmental Health Hazard Assessment (OEHHA) Cyanobacteria Harmful Algal Blooms (HABs) and Cyanotoxins in Recreational Waters	2	All 2 entries resolved for us.
Colorado	Colorado Parks and Wildlife Water Conditions Statewide Colorado Lake and Reservoir Management Association Guidance Document for Harmful Algal Blooms in Colorado	2	All 2 entries resolved for us. The second entry is titled for a Colorado lake-management association and links to the Colorado health department’s toxic algae page, the same URL filed under Connecticut.
Connecticut	Connecticut Department of Energy and Environmental Protection, Blue-Green Algae Blooms Connecticut Department of Public Health Section, Blue-Green Algae Blooms Interim guidance to Local Health Departments For Blue–Green Algae Blooms in Recreational Freshwaters Connecticut Long Island Sound Monitoring	4	All 4 entries resolved for us. The third entry is titled for Connecticut and links to cdphe.colorado.gov, the Colorado health department, which is the same URL EPA uses under Colorado. Start at the two portal.ct.gov entries.
Delaware	Delaware Department of Natural Resources and Environmental Control, Division of Water: What is a Red Tide? Delaware Health and Social Services Frequently Asked Questions: Cyanobacteria (pdf) Delaware National Resources and the University of Delaware’s Citizen Monitoring Program	3	All 3 entries resolved for us.
District of Columbia	District of Columbia Department of Energy and Environment, Algae Blooms in District Waters	1	The single entry resolved for us.
Florida	Florida Department of Environmental Protection: Blue-Green Algae Information Florida Department of Environmental Protection Bureau of Labs, Biology Section Florida Fish and Wildlife Conservation Commission: Blue-Green Algae (Cyanobacteria) Florida Department of Health, Bureau of Environmental Health, Aquatic Toxics Program Protecting Florida Together: Water Quality Status Map Florida Fish and Wildlife Conservation Commission: Red Tide Current Status Blue-Green Algae Task Force South Florida Water Management District: Addressing Blue-Green Algal Blooms	8	All 8 entries resolved for us.
Georgia	Georgia Department of Public Health, Coastal Health District, Harmful Algal Bloom Georgia Department of Public Health, Coastal Health District: Frequently Asked Questions About Blue-Green Algae (Cyanobacteria) and Their Toxins Georgia Department of Natural Resources, Environmental Protection Division, Harmful Algal Blooms	3	All 3 entries resolved for us.
Hawaii	Hawaii State Department of Health Disease Outbreak Control Division: Stinging Seaweed Disease (Lyngbya) Hawaii State Department of Health Disease Investigation Branch: Ciguatera Fish Poisoning (pdf)	2	All 2 entries resolved for us.
Idaho	Idaho Department of Environmental Quality HABs Advisories Idaho Department of Health and Welfare: Harmful Algal Blooms	2	All 2 entries resolved for us.
Illinois	Illinois Department of Public Health Harmful Algal Blooms (HABS) Illinois Environmental Protection Agency: Reporting a Harmful Algal Bloom	2	All 2 entries resolved for us. The first entry is credited to the Illinois Department of Public Health and links to epa.illinois.gov, the Illinois EPA.
Indiana	Indiana Department of Environmental Management, Addressing concerns about Blue-green Algae Indiana Department of Environmental Management: Blue-Green Algae Sampling Resource List Indiana Department of Environmental Management’s Blue-Green Algae Indiana State Department of Health, HAB Map	4	All 4 entries resolved for us. Three entries are credited to the Indiana Department of Environmental Management. Two of them link to in.gov/boah, which is the Indiana State Board of Animal Health, a different agency and the one with the veterinary material.
Iowa	Iowa Department of Health and Human Services, Harmful Algal Blooms Iowa Department of Natural Resources Iowa Department of Natural Resources, Beach Monitoring	3	All 3 entries resolved for us. The second entry links to the department’s front page rather than a HAB page.
Kansas	Kansas Department of Health and Environment, Blue Green Algae	1	The single entry resolved for us.
Kentucky	Kentucky Department for Environmental Protection: Division of Water: Harmful Algal Blooms Kentucky Energy and Environment Cabinet, Harmful Algal Blooms, Division of Water	2	All 2 entries resolved for us. The first entry links to a cabinet landing page rather than a HAB page. The second entry is the Division of Water HAB page.
Louisiana	Louisiana Department of Environmental Quality - Harmful Algal Blooms Louisiana Department of Health Office of Public Health Louisiana Department of Health Safe Drinking Water Program	3	All 3 entries resolved for us. Two of the three entries are department landing pages rather than HAB pages.
Maine	Maine Department of Environmental Protection, Algal Toxins Maine Department of Marine Resources: Red Tide in Maine Maine Department of Environmental Protection, Blue Green Algae Map	3	All 3 entries resolved for us.
Maryland	Maryland Department of Natural Resources, Harmful Algal Blooms in Maryland Maryland Department of Natural Resources, Algae	2	All 2 entries resolved for us. The second entry is credited to the Department of Natural Resources and links to mde.maryland.gov, the Maryland Department of the Environment.
Massachusetts	Massachusetts Department of Public Health, Environmental Toxicology Program, Algae Massachusetts Department of Health and Human Services, Algae Monitoring	2	0 of 2 resolved for us. 2 returned 403 to our request, which is a block on our end and not evidence the page is gone. The second entry links to a statewide alerts page rather than an algae page.
Michigan	Michigan Department of Environmental Quality: Harmful Algal Blooms	1	The single entry resolved for us.
Minnesota	Minnesota Department of Health Blue-Green Algal Blooms and Microcystin Minnesota Department of Health Harmful Algal Blooms Fact Sheet Minnesota Pollution Control Agency, Blue-green Algae and Harmful Algal Blooms	3	All 3 entries resolved for us.
Mississippi	Mississippi Department of Environmental Quality: Beach Monitoring Program Mississippi State University Extension: Planktonic Algae	2	All 2 entries resolved for us.
Missouri	Missouri Department of Health and Senior Services, Algal Blooms Missouri Department of Health and Senior Services, Recreational Water Safety Missouri Department of Natural Resources, Harmful Algal Blooms and Blue-Green Algae	3	1 of 3 resolved for us. 2 returned 404. Both Department of Health and Senior Services entries return a Missouri page reading Page not found. The Department of Natural Resources entry redirects to a working HAB page.
Montana	Montana Department of Public Health and Human Services: Public Health & Safety: Harmful Algal Blooms Montana Department of Environmental Quality Harmful Algal Blooms Page	2	All 2 entries resolved for us.
Nebraska	Nebraska Department of Health and Human Services and the Nebraska Department of Environmental Quality: Fact Sheet - Precautions and facts regarding toxic algae at Nebraska Lakes Nebraska Department of Environmental Quality: Beach Watch HABs	2	All 2 entries resolved for us.
Nevada	Nevada Department of Wildlife Harmful Algal Bloom Webpage Nevada Division of Environmental Protection - Harmful Algal Bloom Program	3	All 3 entries resolved for us. Two of the three entries point at the same Department of Wildlife page under different titles.
New Hampshire	New Hampshire Department of Environmental Services: What You Should Know About Cyanobacteria	1	0 of 1 resolved for us. 1 returned 403 to our request, which is a block on our end and not evidence the page is gone.
New Jersey	New Jersey Center for Water Science and Technology New Jersey Department of Environmental Protection Harmful Algal Blooms website New Jersey Department of Environmental Protection, HABs in Drinking Water Supply Freshwater Cyanobacterial Harmful Algal Blooms Response Strategy (pdf) Freshwater Cyanobacterial HAB Fact Sheet (pdf) Freshwater CyanoHABs and CyanoToxins: Recreational Exposure and Health Effects Fact Sheet (pdf) Freshwater Cyanobacterial Harmful Algal Blooms Online Reporting Form Marine Harmful Algal Blooms Fact Sheet (pdf) New Jersey Department of Environmental Protection, HAB	9	8 of 9 resolved for us. 1 returned 404. The Montclair State University entry returns Page Not Found. The other eight, including three state fact sheets and the reporting form, resolved.
New Mexico	New Mexico Environment Department - Harmful Algal Blooms	1	The single entry resolved for us.
New York	New York State, Department of Environmental Conservation: HABs Harmful Algal Blooms (HABs) Program Guide	2	1 of 2 resolved for us. 1 returned 403 to our request, which is a block on our end and not evidence the page is gone.
North Carolina	North Carolina Department of Health and Human Services, Blue-Green Algae North Carolina Environmental Quality, Algal Blooms North Carolina Department of Environmental Quality, HABs Monitoring	3	All 3 entries resolved for us.
North Dakota	North Dakota Department of Environmental Quality: HABs North Dakota Game and Fish Department, HABs	2	All 2 entries resolved for us.
Ohio	Ohio Environmental Protection Agency: Algal Toxin Analysis Options (pdf) Ohio Environmental Protection Agency: Algae Information for Public Water Systems Ohio Environmental Protection Agency: Algae Information for Recreational Water	3	All 3 entries resolved for us.
Oklahoma	Oklahoma Department of Environmental Quality: HABs Oklahoma Tourism and Recreation Department Harmful Algal Bloom Oklahoma State Department of Health: Blue Green Algae	3	All 3 entries resolved for us.
Oregon	Oregon Health Authority: Blue-Green Algae Labs and Expert Contacts List Oregon Health Authority, Harmful Algal Bloom Surveillance Program Oregon Health Authority, Algae Resources Oregon Health Authority, Algae Bloom Advisories	4	All 4 entries resolved for us.
Pennsylvania	Pennsylvania Department of Health, Harmful Algal Blooms Erie County Department of Health, Pennsylvania, HABs Map PA Department of Environmental Protection/Harmful Algal Blooms	3	All 3 entries resolved for us. The Erie County entry lands on a county health department home page rather than the HABs map named in the title.
Rhode Island	Rhode Island Department of Environmental Management, HAB (marine) Rhode Island Department of Environmental Management, Cyanobacteria (Blue Green Algae) (freshwaters)	2	All 2 entries resolved for us. The entry titled for marine HABs links to an aquatic invasive species page.
South Carolina	Cyanobacteria: Understanding Blue-Green Algae’s Impact on Our Shared Waterways, South Carolina Waterways, Clemson University South Carolina Department of Health and Environmental Control, Harmful Algal Blooms South Carolina Beach Guide	3	2 of 3 resolved for us. 1 returned 403 to our request, which is a block on our end and not evidence the page is gone.
South Dakota	South Dakota Department of Health, Algal Toxins/Cyanobacterium	1	The single entry resolved for us.
Tennessee	Tennessee Department of Environment and Conservation Harmful Algal Blooms	1	The single entry resolved for us.
Texas	Texas Parks and Wildlife Department, Harmful Algal Blooms Guide for Public Health Response to Cyanobacterial Harmful Algae in Recreational Freshwater in Texas (pdf) Texas Health and Human Services: Harmful Algal Blooms – Seafood and Aquatic Life	3	All 3 entries resolved for us.
Utah	Utah Department of Environmental Quality HABs Utah Department of Health: HABs Chemtech-Ford Laboratories Utah Department of Environmental Quality, HAB Map	4	All 4 entries resolved for us. One of the four entries is a commercial testing laboratory rather than a public agency.
Vermont	Vermont Department of Health, Cyanobacteria, Blue-Green Algae in Lake Champlain Vermont Department of Health Veterinarian Fact Sheet (pdf) Vermont Department of Environmental Conservation, Water Quality Division, Cyanobacteria toxins Vermont Department of Environmental Conservation, Drinking Water and Ground Protection Division, Public Drinking Water System - Cyanobacteria monitoring Vermont, HAB Map	5	All 5 entries resolved for us. The Department of Environmental Conservation entries land on agency front pages rather than cyanobacteria content. The health department tracker is the working entry.
Virginia	Virginia Department of Health: HAB Virginia Department of Health: Algal Bloom Surveillance Map	2	All 2 entries resolved for us.
Washington	Washington State Department of Health, Division of Environmental Health, Cyanobacteria (Blue-Green Algae) Washington State Toxic Algae, Freshwater Algae Bloom Monitoring Program Washington State Toxic Algae Online	3	All 3 entries resolved for us.
West Virginia	West Virginia Department of Health and Human Resources, Information on Cyanobacterial Blooms (Blue-green Algae Blooms) or Harmful Algal Blooms West Virginia Department of Health and Human Resources, Harmful Algal Bloom Response Plan for Recreational Waters	2	All 2 entries resolved for us.
Wisconsin	Wisconsin Department of Health Services, Blue-Green Algae Wisconsin Department of Natural Resources Blue-Green Algae website Public Health Madison-Dane County Beaches Wisconsin Department of Natural Resources, Beach Health	4	All 4 entries resolved for us.
Wyoming	Wyoming Department of Environmental Quality, Harmful Cyanobacterial Bloom, Current Advisories	1	The single entry resolved for us.

How to use that table

1. Open your state’s own page first. Every one of the six state frameworks quoted above publishes its tier definitions on its own site. Read the definition next to the status word, not the status word.
2. Look for the pet line specifically. Oregon puts a pet line in its tier definitions, and Kansas puts one in its Watch and Warning definitions but not in Hazard, where its general animal instruction still applies. Utah’s tier definitions have none. If your state’s tiers do not mention animals, the status is a human status and you are on your own for the rest.
3. Check whether the number was measured anywhere near where your dog will be. If the page names a swimming beach, that is where the sample came from.
4. Note the date on the status. Oregon’s table carries a date per waterbody, and on the day we read it, the page also carried a notice that it would not be updated for ten days.
5. If your state’s page is one of the ones we found broken, go to the agency’s own site and search from there rather than concluding the state publishes nothing. A dead link in a federal directory is a dead link, not a missing programme.

Freshwater Only: Why This Page Stops at the Coast

This page covers freshwater cyanobacteria. It does not cover marine or coastal harmful algal blooms, and that boundary is not tidiness. The organisms differ, the toxins differ, and one exposure route has no freshwater equivalent. EPA states: “There is one marine HAB, the red tide forming Karenia brevis, that can be aerosolized through wave action and has been implicated in respiratory illness from exposure through breathing the aerosols.” Nothing on this page about drinking, grooming or shoreline scavenging addresses breathing aerosolised toxin on a beach.

Watch for this when you use any state directory, because state HAB programmes cover both and file them together. In EPA’s directory alone, Maine’s entry includes a Department of Marine Resources red tide page, Delaware’s includes one titled “What is a Red Tide?”, Florida’s includes a red tide current status page from its Fish and Wildlife Conservation Commission, Hawaii’s entries are ciguatera fish poisoning and stinging seaweed disease, Alabama’s single entry is a coastal beach monitoring programme, and Rhode Island lists its marine and freshwater resources as two separate entries. Several of those are useful pages. None of them is about the pond your dog swims in.

If you are on the coast, the freshwater guidance here is the wrong guidance, and you want your state’s marine programme.

Your Algal Bloom Checklist

Before you go

• Find your state’s own HAB page from the table above, and bookmark the agency page rather than the federal directory entry, since the directory entry is what rots.
• Read your state’s tier definitions once, on a calm afternoon, and write down which words it uses. Warning is a middle tier in Kansas and California, the lower of two in Utah, and does not exist in Oregon, Wyoming or Idaho.
• Check whether any tier definition in your state mentions pets. If none does, treat every posted status as a human status.
• Look for whether your state publishes a separate animal value. Oregon and Indiana do; EPA’s threshold compilation is where to check, with the caveat EPA attaches, that it lists only thresholds it found publicly available.
• Pack water for the animal on every trip to open water, so that the lake is never the drinking source even when everything looks fine.
• Carry rinse water in addition to the animal’s drinking water, in a volume that will actually rinse a coat, plus soap if your state names it. Indiana, Idaho and Oregon do.
• Put gloves in the car or the day pack. EPA’s dog guidance is to wear them while rinsing a possibly exposed animal.

At the water

• Look for scum, foam, mats, discoloration or a bad smell. EPA’s dog page groups those into three signs, and hedges the smell with “Some (but not all)”.
• Do not treat clear water as cleared water. EPA states you cannot tell whether a bloom is harmful by looking at it, and Oregon documents four dog deaths at Elkton in 2009 where no visible bloom was reported.
• Keep the animal off the shoreline, not just out of the water. EPA states that wind drives blooms to amass on shorelines and that those accumulations are larger than blooms in open water.
• Do not let the animal eat anything at the edge. Dried and stranded material is the concentrated form, and EPA’s 2019 document puts scums at thousand-fold to million-fold cell concentrations.
• Do not fill a bowl from the lake, and do not try to fix lake water. Idaho states boiling concentrates cyanotoxins and that most backpacking filters do not remove them; Wyoming states boiling, filtration and other treatments will not remove toxins.
• Treat a posted advisory as a floor on the danger rather than a ceiling, and treat a lifted or milder status as information about people rather than about the animal.

If the animal got in

• Rinse immediately, with gloves on, before the animal grooms itself. EPA, Indiana, Idaho, Oregon, California and Wyoming all publish a rinse instruction; Indiana, Idaho and Oregon name soap, EPA’s two pages name clean fresh water and tap water.
• Rinse with the water you brought, not in the lake. None of those agencies names the waterbody as the rinse source. If you have no clean water with you, keeping the animal from licking its coat is the interim step until you reach some.
• Stop the licking. EPA and Indiana both instruct specifically against letting the animal lick material off its fur.
• Call the veterinary practice rather than waiting for symptoms, if the animal drank the water or ate or licked scum. EPA states to seek veterinary care immediately in that case.
• Say the words harmful algal bloom on the phone, and say when and where. California states that doctors and veterinarians may not be familiar with cyanotoxin exposure.
• Watch for the full window, not the first hour. EPA states symptoms can arise anywhere from 15 minutes to several days after exposure.
• File the bloom report and, if the animal is ill, the animal illness report. EPA’s dog page says to report the bloom to your state’s health department, and in Kansas a complaint is what triggers sampling in the first place.

For a pond you own

• Assume no agency is monitoring it. Wyoming states its programme focuses on publicly accessible waterbodies used for full-body contact recreation.
• Fence and re-route rather than reaching for chemicals first. Indiana’s Board of Animal Health publishes fencing off downwind drinking areas and using other water sources among its prevention steps, and separately warns that algaecides and herbicides break the cells open and release toxins rapidly.
• Take the treatment question to a veterinarian or your state extension service, because Indiana’s own page carries statements pointing in both directions on chemical treatment.

Where to Go Next

This page is one spoke of our pet emergency playbooks hub, and it answers a narrow question: what a posted algal bloom status does and does not tell you about an animal.

If the hazard is your household’s tap rather than a lake. Our page on pets and a boil water advisory covers the advisory types, which ones boiling fixes and which ones it makes worse, and the fridge, filter and fish tank cases that municipal notices leave out.

If the animal came out of the water covered in something. Our floodwater washing guide works through the sequence for getting contaminated water off a coat, which is the same physical job as the rinse described here even though the contaminant is different.

If the water source is out and you need to know how long you have. Our page on how long a dog can go without water covers the timeline, and it is the right page for the moment when the honest answer at the lake is that the animal drinks nothing from it.

If the trip is on the water rather than beside it. Our dog overboard guide covers the recovery sequence for a dog that goes in unexpectedly.

Then do the one thing that pays off most, and it takes about ten minutes. Open your own state’s HAB page from the table above, find its tier definitions, and read them once now rather than on a hot Saturday with a wet dog and a sign you have never seen before. Write down whether any tier in your state mentions pets at all. If none does, you have learned the most useful thing on this page: the sign at your lake is not going to answer your question, and the water you brought with you is.