Algae Alert: Understanding the Dangers of Blue-Green Algae for Pets

What is blue-green algae?

Blue-green algae is actually not algae at all, but a type of bacteria known as cyanobacteria that thrives in warm, nutrient-rich conditions and can form dense clusters known as blooms. The blooms typically occur during warmer months, when nutrients are abundant, often from runoff containing fertilizers or animal waste. Stagnant water, increased sunlight, and low rainfall also contribute to the blooms’ rapid growth.

Water affected by cyanobacterial blooms may appear green, blue, yellow, red, or brown, often with a thick mat of green or blue-green scum on the surface. The water can look similar to spilled paint or pea soup, and sometimes the blooms produce a swampy odor.

What are blue-green algae poisoning signs in pets?

Blue-green algae poisoning, also known as cyanobacterial toxicosis, manifests rapidly in dogs, typically 15 minutes to several hours after exposure. The primary toxins are microcystin and anatoxin, which pose severe health risks to pets. Microcystin can cause profound liver damage, leading to liver failure and potentially death in hours to days. Anatoxin affects the nervous system, leading to neurologic issues, such as seizures, excessive salivation, and rapid death, if not treated immediately. Both toxins can cause shock, respiratory arrest, and rapid death.

Initial signs can vary, but commonly include:

• Vomiting
• Diarrhea
• Drooling
• Weakness
• Pale gums

As the condition progresses, more severe signs, such as muscle tremors, difficulty breathing, paralysis, and seizures, may develop.

What should I do if my pet has been exposed to blue-green algae?

If you suspect your pet has been exposed to blue-green algae, rinse them with fresh, clean water to remove any algae from their fur and ensure they do not lick and ingest the toxic bacteria. If your pet has poisoning signs, such as vomiting, diarrhea, or disorientation, or you know they have consumed contaminated water, seek immediate veterinary care.

How is blue-green algae poisoning treated in pets?

Since no specific antidote is available for cyanotoxins, supportive care is vital. Treatment may include:

• Decontamination — Procedures such as inducing vomiting, performing gastric lavage, or administering activated charcoal may be recommended to prevent further toxin absorption.
• Intravenous (IV) fluids — Intravenous fluid therapy may be administered to combat dehydration and maintain blood pressure.
• Oxygen therapy — An oxygen cage or flow-by oxygen may be needed to support breathing if your pet is in respiratory distress.
• Blood products — Administration of whole blood or fresh frozen plasma may be necessary if your pet has signs of significant internal bleeding or to manage shock.

Throughout the treatment process, continuous monitoring and adjustments based on your pet’s therapy response and progression of clinical signs are essential. Immediate and aggressive treatment increases the chances of recovery, highlighting the importance of quick action and specialized care in blue-green algae poisoning cases.

How can I prevent my pet from getting blue-green algae poisoning?

Preventive measures are essential when protecting pets from blue-green algae. They include:

• Avoiding stagnant waters — Don’t let your pet drink or swim in stagnant ponds, lakes, or discolored bodies of water with bluish-green scum, foam, or algal blooms on the surface or edges.
• Providing water — Always ensure your pet has clean, fresh water, especially when outdoors or hiking, to discourage them from drinking from natural sources that may be contaminated.
• Rinsing after swimming — If your pet swims in natural water bodies, rinse them thoroughly with clean water immediately after to remove any algae from their fur.
• Using life jackets and leashes — Ensure your pet wears a life jacket near water and leash them to maintain control and avoid dangerous areas.
• Watching for warnings — Local health departments often test water and may post signs indicating unsafe conditions. Always check for warnings and monitor local advisories before allowing your pet near water.

By adopting these strategies, you can significantly mitigate the risks of blue-green algae and ensure your pet’s safety outdoors. However, always err on the side of caution—if you are unsure about quality, keep your four-legged friend out of the water. If you suspect blue-green algae poisoning in your pet after swimming, contact your AAHA-accredited veterinarian for help.