Blue-green Algae (Cyanobacteria)
Poisonous to: Cats, Dogs
Level of toxicity: Generally moderate to severe
Common signs to watch for:
- Blood in stool or black, tarry stool
- Pale mucous membranes
- Excessive secretions (e.g., salivation, lacrimation, etc.)
- Neurologic signs (including muscle tremors, muscle rigidity, paralysis, etc.)
- Blue discoloration of the skin and mucous membranes
- Difficulty breathing
Dogs that enjoy swimming and playing in lakes and ponds may be exposed to blue-green algae. Hunting dogs are especially predisposed due to increased exposure outdoors. Clinical signs of poisoning are dependent on the toxin involved. Microcystins can result in liver damage or failure. Signs of liver injury include vomiting, diarrhea, blood in stool or black, tarry stool, weakness, pale mucous membranes, jaundice, seizures, disorientation, coma, and shock. Death generally follows within days as a result of liver failure. Blood work changes include elevated liver enzymes, a low blood sugar, a low protein, and even abnormal clotting. Aggressive, immediate treatment is necessary to help treat this quick-acting, potentially fatal poison!
Anatoxins result in neurotoxicity evidenced by excessive secretions (e.g., salivation, lacrimation, etc.), neurologic signs (including muscle tremors, muscle rigidity, paralysis, etc.), blue discoloration of the skin and mucous membranes, and difficulty breathing. Death follows within minutes to hours of exposure as a result of respiratory paralysis. Livestock that graze around affected ponds or lakes and are able to drink from them are often found dead near the water source. Treatment includes anti-seizure medication, oxygen, and aggressive care by your veterinarian.
Unfortunately, there is no antidote for the toxins produced by blue-green algae. Immediate veterinary care is imperative. If you suspect your dog was exposed to blue-green algae, contact Pet Poison Helpline immediately for guidance.
Poison type: plants
Alternate names: Cyanobacteria, algal, Microcystis, Anabena, Aphanizomenon, cyanotoxin, anatoxin