The Idaho Division of Public Health works with Idaho’s local public health districts to investigate outbreaks of illness linked to drinking water and recreational water. We also provide information about well water safety and harmful algal blooms in the state.
CyanoHABs are harmful algal blooms made of cyanobacteria. These bacteria can grow quickly in warm, nutrient-rich water and sometimes produce toxins that are dangerous to people and animals.
CyanoHABs can look like paint, foam, scum, or mats on the surface of lakes and ponds. They may be blue, green, brown, or red.
People and animals can be exposed to harmful toxins by:
- Swallowing, breathing in, or touching affected water while swimming, fishing, or water skiing
- Eating fish caught from water with a bloom
Exposure to cyanoHAB toxins may cause:
- Skin or eye irritation
- Nausea or vomiting
- In severe cases, death
To stay safe, keep your family and pets away from water that looks discolored or has surface scum.
Cyanobacterial Harmful Algal Bloom Resources
Animal Exposure
Is it safe for my dog to go in the water during a harmful algal bloom caused by cyanobacteria?
No, it is not safe. Dogs are more likely than people to be exposed to cyanotoxins. They can get sick from:
- Drinking contaminated water
- Swallowing water while swimming or retrieving toys
- Licking cyanobacteria off their fur
- Eating mats of cyanobacteria
- Eating dead animals, like fish, near the bloom
- Retrieving birds that swam through a bloom and have cyanobacteria on their feathers
Bring clean drinking water for your dog when you are near a lake or river with a harmful algal bloom. Keep your dog on a leash if it tends to eat or chew on things it finds.
What should I do if my dog goes into the water during a harmful algal bloom?
- Rinse your dog immediately with clean water.
- Then contact your veterinarian, the ASPCA Animal Poison Control Center at 1-888-426-4435, or the Pet Poison Helpline at 1-855-764-7661. (These services charge a fee.)
- Dogs can get sick within minutes to hours after being exposed. The symptoms depend on the type of toxin and how your dog was exposed.
- Do not call the Idaho Department of Environmental Quality or public health officials for diagnosis or treatment. They will refer you to your veterinarian or one of the animal poison hotlines listed above.
My dog got sick or died after swimming in a lake or river. Will a public agency pay for testing my dog?
No. Pet testing is the responsibility of the pet owner. There are currently no commercial tests to confirm cyanotoxin poisoning in dogs.
Public health agencies in Idaho test water when a harmful algal bloom is suspected.
You can report a suspected bloom to the Idaho Department of Environmental Quality using the Report a Potential Bloom form or link.
Learn more:
Recreational water includes any natural or man-made water used by many people for activities like swimming or playing. This includes:
• Lakes
• Rivers
• Pools
• Splash pads
• Hot tubs
Using recreational water can have many health and wellness benefits. However, illnesses can spread when people swallow, breathe in, or come into contact with contaminated water.
The Centers for Disease Control and Prevention (CDC) has reported an increase in outbreaks of diarrheal illness related to recreational water use. These illnesses often occur during the swimming season.
Use caution and look for signs of poor water quality when recreating in and around recreational water.