Harmful Algal Bloom (HAB) Information
Overview
Harmful algal blooms (HABs) can produce toxins that are dangerous to all animals, including humans. Algae and cyanobacteria (also called blue-green algae) live in water, both freshwater and saltwater, and sometimes can grow out of control or “bloom." Some, not all, of these blooms produce toxins that can make people and animals sick. Illness can range from mild to severe and can sometimes result in sudden death.
HABs are more common when water is warm, stagnant, and full of nutrients. Excess nutrients can come from agricultural lands, livestock waste, leaky septic systems, storm runoff, and other sources. The Center for Disease Control (CDC) is a resource for photos of what blooms may look like, but remember, you cannot tell if it is toxic just by looking at it (CDC Harmful Algal Blooms).
How can animals be exposed
Animals can be exposed to HAB toxins through direct contact with or ingestion of contaminated water (including water spray or mist). This exposure may occur by swimming or wading in contaminated bodies of water, drinking contaminated water, or by eating floating mats/algal scum or dried crusts along water shorelines. Exposure may also occur if an animal licks their fur/coat after direct contact with contaminated water.
Signs of HAB exposure in animals
Signs of HAB exposure in animals may indicate exposure to hepatotoxins (toxins that affect the liver), neurotoxins (toxins that affect the nervous system), or dermatoxins (toxins that affect the skin, or respiratory tract if inhaled). Clinical signs may occur within 30 minutes to a few hours after exposure. Depending on the specific animal, exposure, and toxin, clinical signs may include:
- Vomiting and diarrhea
- Increased salivation
- Rash, hives
- Fatigue
- Stumbling, difficulty walking or standing
- Shortness of breath, coughing
- Weakness
- Seizure like activity
- Liver failure, jaundice
- Death
How to reduce animal exposure to HABs
- Prevent animal access to suspected contaminated water (e.g., use fencing for livestock; keep dogs on leash and do not let them swim or wade in the water).
- Prevent animals from licking their fur/coat after getting out of water.
- Do not let animals eat floating mats/algal scum or beach debris.
Current Oregon HAB Advisories
The Oregon Health Authority (OHA) issues HAB recreational use health advisories for monitored or sampled water bodies in Oregon. These advisories can be found on the OHA website:
https://www.oregon.gov/oha/PH/HEALTHYENVIRONMENTS/RECREATION/HARMFULALGAEBLOOMS/Pages/Blue-GreenAlgaeAdvisories.aspx
What to do if your animal has potentially been exposed to HAB
- Eliminate animal access to the contaminated (or suspected contaminated) water source. An alternate source for drinking water may be necessary (e.g., for livestock).
- Wash animals with clean water to remove algal debris and monitor for signs of toxin exposure.
- If animal exhibits signs of exposure (or confirmed exposure has occurred) seek veterinary care immediately.
- Report suspected harmful algal bloom or related animal illness to the Oregon Health authority via their HAB Animal Illness Report Form (available on the Current Cyanobacteria Advisories webpage)
Resources
Other Oregon State Agency Resources
Other Resources
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