- Angela De Palma-Dow
- Posted On
Lady of the Lake: Keeping your furry friends safe in Clear Lake

Dear Lady of The Lake,
We will be visiting our relatives that live on Clear Lake and we have pets. We have an older large lab and a smaller dog and we are wondering if they can safely swim and go into Clear Lake? I have heard stories and sometimes see posts on social media about dog illnesses and death after they visit Clear Lake. Please help us keep our furry friends and family safe!
Thank You,
The Barney family including Cha-Cha and Big Bear (the dogs!)
Dear Barneys,
On behalf of pet owners everywhere, thank you for asking this question! Another big thank you for being such responsible pet owners and being concerned about your pet’s safety.
As pet owners, we know that our pets are basically helpless and we are the ones that have to make the decisions for them to keep them safe and healthy. Furry friends are extended members of the family, and when they get hurt or are sick, we feel for them.In some cases, people don’t have kids - they just have cats or dogs!
It’s great that you are taking care of your fur family and making sure they are safe when recreating on Clear Lake - or any natural water body.
You might be surprised, but in my day job, I get about the same number of phone calls about pets and water safety as I receive about people and water safety. I also have many friends who regularly take their pets out on lakes and streams, and they call or text me to report local conditions and to ask questions about water quality.
The biggest concern for pet owners when recreating on Clear Lake is potential toxicity from cyanobacteria, or harmful algal blooms (HABs). Sometimes cyanobacteria are called blue-green algae, and they can sometimes produce green globs, thick mats, or clumps and films that can appear bright green, blue, teal, white, purplish, or red. Sometimes the cyanobacteria just makes the water thick, like pea soup, and sometimes they appear on the surface of the water in thick streaks, with paint-like films.
Cyanobacteria are single celled organisms that float in the water column. They can not be seen with the naked eye unless they reproduce into such large numbers that you can see them as colonies or globs floating in the water, called blooms. When you look closely, you can identify if they are globular or sometimes they look like small shards or irregularly shaped clumps.
Some genera of cyanobacteria can produce toxins, grouped together called cyanotoxins, that can be a health hazard to pets, children, livestock, wildlife, or people, depending on the exposure route, duration, and the toxin type.
First, let's define and discuss these terms:
Exposure route is defined as the pathway that contaminants can enter the body, including dermal, inhalation, and ingestion. To put it plainly, exposure can occur directly through the skin, breathing in water particles that contain toxins, or through consumption, like eating and drinking.
Duration refers to the time the exposure to the toxins occurred. So how long or short was the pet in the water when they could have been exposed. Duration might also include how long the pet was wet before being rinsed or bathed, after they got out of the water where they got exposed.
Toxin type, refers to the type of compounds that comprise the toxin that is produced by some cyanobacteria. They are named for their toxicological target, or what part of the body they impact, and include hepatotoxins, neurotoxins, cytotoxins, dermatotoxins, and irritant toxins. Neurotoxins, which can affect the nervous system, are more concerning than irritant toxins or dermatotoxins, which might only cause a rash or itching.
Cyanobacteria affect humans and animals differently; some people and pets are more or less sensitive to a certain type of cyanobacteria, or not at all. They are sometimes like allergies, where the response can be negligible, mild, or severe and cause sickness.
You might not know how a pet will react to water conditions, meaning that just because someone else’s dog is swimming and playing in the water and seems fine, doesn’t necessarily mean your dog will have the same reaction or non-reaction. It’s best to know how and when to identify if a water body is undergoing a potentially toxic bloom event and what to do in case your pet becomes exposed.
Recognizing blooms and knowing when the water is safe for pets
If you are accessing a public beach or park on the water, make sure to be aware of any posted signs, permanent or temporary, that could contain useful and current information about blooms being detected in the area. If you are unsure of conditions, you can always call an Environmental Health, Public Health, or Water Resources office, to get more information or get directed to where you can find more information.
Not all waters have cyanobacteria blooms that produce toxins, and cyanobacteria blooms that produce toxins are not present all the time throughout a season or a year. Clear Lake is a very big lake, and blooms can be present in some areas and during some times of the year while not present in others.
Cyanobacteria are usually single-cellular and can form colonies and dense mats at the surface of the water due to buoyant chambers some genera produce. The buoyancy characteristics of cyanobacteria means they can make themselves float at the surface of the water, usually in dense colonies. Cyanobacteria, when they grow in dense colonies can look like globs or mats or even look like spilled light blue or even white paint!
Need help identifying a bloom, mat, aquatic plants, or foam? Refer to this California Water Board HAB and Non-HAB visual guide.
Usually there are parts of the lake where there are no cyanobacteria present, and pets can enjoy the water. You can usually physically see - or smell! - when there is a problematic bloom, but unfortunately, toxins can be present sometimes when there is not a visible bloom. However, this doesn’t occur that often, and keeping your pet out of water that is questionable is the best, safest course of action.
A general good rule of thumb to follow is; “when in doubt, keep them out!”. If you wouldn’t swim in the water, then your pet should probably also not go in.
Of course, the best method to determine if an area of the Lake has toxins is through water monitoring and lab analysis. The Big Valley Band of Pomo Indians EPA department monitors about 20 locations around the lake every two weeks Spring through Fall. They collect samples from the shallow, shoreline area, where people and pets are most likely going to be accessing the water.
You can view the most recent cyanobacteria monitoring data here, at the Big Valley Rancheria Cyanotoxin webpage.
The San Francisco Estuary Institute also has a really species satellite tool that maps the cyanobacteria present in the lake over the last 10-day period based on pigments. This tool does not reflect toxins, but it’s usually a good indicator of general good and bad places around the lake.
While this information is extremely useful for humans, the recommendations for safe recreation thresholds of cyanotoxin concentrations in samples are based on the science for adult, male, humans - not pets or animals!
Since pets, usually dogs, are much smaller than humans, smaller concentrations or smaller exposure time, might lead to sickness when a human would not be impacted.
Additionally, humans know not to drink the lake water, but dogs don’t know that, and would probably like the taste of green, globby water if given a choice.
Lastly, and obviously, humans don’t lick themselves after being in the Lake, but guess who does? Man’s best friend can become exposed to toxins that remain on wet fur after the dog has left the water.
If you are at a water access site, in Clear Lake, or any natural waterbody, and you notice a bloom, play it safe and assume it is producing toxins. Don’t let your pets drink the water, or play in the water, don’t let livestock eat near the lake shore, as grass that has been irrigated or splashed with lake water could be covered with live toxins.
Don’t let dogs or pets eat the bloom mats or any dead animals or trash that is in the water or near the water's edge, and lastly, don’t let dogs lick their fur after they get out of the water, until they have been rinsed or washed with clean, filtered or tap water.
What to do if your pet has been in the water or been exposed?
As pet owners we know that pets don’t always listen to us and they sometimes run off and do things out of our line of vision. That’s why it’s good to be prepared in the event that your pet does come into contact with the water. There are some easy, free things you can do to reduce and limit the chance of them becoming exposed or sick from exposure to cyanobacteria toxins.
Make sure your pet is hydrated and has lots of clean, drinking water options. There are several types of water bottle- bowl contraptions that travel well that make it fun for dogs to drink clean water on the go, so they are less likely to be extremely thirsty and gulp lake water.
You don’t need a fancy drinking water bowl, a clean poop-clean up bag will work as a bowl if needed in a pinch! The goal is to limit the potential for your pet to want to drink the lake water, so give your pet fresh water as much as possible prior to and during water play.
Bring lots of clean water so you can rinse off your pet after they have played or waded in the lake. Rinsing with clean water and drying with a clean towel, rug, or blanket, is the best option for removing the toxins from the wet fur. Once you get home, a more thorough wash or plunge in a clean pet pool will remove any remaining toxin and prevent any skin irritations that were initially unobvious.
If you are kayaking or paddle boarding with your pet, these activities greatly reduce the exposure potential for pets, however if they fall in or lean over to drink the water, they will be exposed and become susceptible to any toxins present.
Some dogs love to swim and can inadvertently drink the water they are swimming in. Providing your pooch a life vest or float shirt will help keep their head raised above the water, and they will be less likely to ingest lake water. This is also helpful to prevent a tired pet from being in the water longer, increasing exposure. If they are wearing a life vest, they can swim easier to shore and will be spending less time in the water.
And lastly, if you think your pet has been exposed and is becoming sick or ill from being in the water, take them to your veterinarian immediately. Make sure to tell the vet that the pet was in a natural water body and exposed to cyanotoxins.
Even if it has been a few days, report all information to the vet so they can make the best diagnosis and start treatment. There are some symptoms that can be treated, but without that knowledge of previous water activities, veterinarians might not be able to help your pet.
Some dogs have died after being in Clear Lake because their owners didn’t wash them off after being in the water and then they waited too long to take them to the vet and didn’t communicate the water activities they were engaged in before falling ill. It’s very sad and unfortunate, and possibly could have been prevented.
Video: “Pet Tips, Cyanobacteria & Water Safety” brought to you by County of Lake, Water Resources Department and partners at Send Rover on Over in Lakeport, CA put together this video PSA to help you keep your pets safe when recreating on natural water bodies like Clear Lake.
Let’s review how to keep your furry friend safe when recreating natural waters!
Be a responsible pet owner! Prevent exposure by limiting where and when your pet goes in the water to places that are free of blooms. Take precautions to limit the impact of toxins if they are present in the water, by following all the easy tips that were provided, including:
• Be aware of local conditions, look for any posted signs or warning notices for the area.
• Keep your pet hydrated, and maintain clean, drinking water options before and during their water play.
• Prevent pets from licking their fur during and when they are done playing.
• Rinse or wash your pet immediately after playing in the water.
• If your pet does appear sick, take them to the vet immediately and communicate to your vet any water activities your pet engaged in even if it has been several days.
If you are not sure what cyanobacteria symptoms look like in pets, there is a useful graphic from the CDC describing how to keep pets safe from cyanobacteria toxicity. Here is the full CDC Pets and Cyanobacteria Blooms webpage, which contains lots of useful information necessary for every pet owner.

More information and how to report a bloom or illness
If you want more information on cyanobacteria, beyond that related to pets, you can visit my previous Lady of the Lake column from July 11,2021, “Concerned about Cyanobacteria in Soda Bay."
If you or your pet become sick from a suspected cyanobacteria bloom or toxin exposure, there is a team at the State Of California Office of Environmental Health Hazard Assessment (OEHHA) that wants to know about it and has resources to help you respond, and in some cases can help offset costs for testing. OEHHA can provide specialized guidance that is beyond the resources available at the local level.
To report a health impact from a bloom or cyanobacteria bloom, suspected bloom, from the lake, you can submit a report to OEHHA via the Harmful Algal Bloom Incident Reporting tool, called “Report a Bloom”. You can submit a report here online or by calling their Report a Bloom hotline: 1-844-729-6466 (toll free).
It takes about a minute to fill it out, but it’s essential that the state receives this information so that they can respond and direct more adequate resources to cyanobacteria management and mitigation.
If you are interested in knowing where reports of blooms are in Clear Lake, or other lakes, you can visit the HAB Incident Reports Map.
I hope this column has helped provide you with the needed information to keep your fur family safe while recreating in lakes, reservoirs, streams, and creeks. For many of us, our pets are a precious extension of our family, and just like we would take care of any human family member, we extend that sentiment to our pets.
Sincerely,
Lady of the Lake
Angela De Palma-Dow is a limnologist (limnology = study of fresh inland waters) who lives and works in Lake County. Born in Northern California, she has a Master of Science from Michigan State University. She is a Certified Lake Manager from the North American Lake Management Society, or NALMS, and she is the current president/chair of the California chapter of the Society for Freshwater Science. She can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..