Blue-Green Algae Poisoning in Cats
Key takeaways
Blue algae, also known as cyanobacteria, appears as a blue or green plant-like growth coating the surface of standing bodies of water such as lakes and ponds. Many species of cyanobacteria are highly toxic when ingested by mammals, including cats.
- Cyanobacteria poisoning is uncommon in cats.
- Blue algae colonies produce toxins that result in severe illness when large amounts are ingested during drinking or swimming
- A variety of different organs may be affected including the liver, brain, kidneys, and skin
- Symptoms may include weakness, collapse, muscle tremors, seizures, or sudden death, vomiting, diarrhea, excessive drooling, excessive drinking and urinating, itchiness, and blister, depending on what type of bacteria is present
- Treatment options are limited as there is no specific antidote, treatment focuses on decontamination, supportive care such as fluid therapy, treatment of seizures, and preservation of organ function.
- Prognosis is very poor.
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A closer look: Blue-Green Algae Poisoning in Cats
Blue-green algae refers to a cyanobacteria that is not actually an algae, but rather a type of bacteria that lives on the surface of water and can photosynthesize (the bacteria uses light as its energy source). Its name comes from its vibrant blue-green color. Many species of cyanobacteria are toxic to mammals, including cats, when ingested.
There are over 2000 strains of cyanobacteria and only around 4% produce dangerous toxins. It is not possible to visually determine which colonies produce toxins and which do not.
When symptoms occur they are often severe, and fatality is common. Cats suspected of blue-green algae ingestion or poisoning require emergency veterinary attention.
Risk factors
Blue-green algae poisoning is uncommon in cats. Outdoor cats who have hunting behaviors are at a higher risk. Indoor cats are at no risk unless they escape and are exposed to blue-green algae outdoors. There is also a greater risk of cyanobacteria poisoning in the warmer months when stagnant water has not frozen over.
Symptoms vary significantly from mild to severe depending on which toxins are ingested/contacted, and in what volume, as well which body system is affected.
A mild case may take weeks or months to resolve, whereas a severe case whereas a severe case can be fatal.
A small amount of toxin exposure in a large animal may not cause serious symptoms, but cats are small and therefore susceptible to small doses.
Possible causes
Cyanobacteria poisoning is the result of ingestion of or contact with a range of toxins produced by a group of water-borne bacteria known as cyanobacteria.
Main symptoms
Symptoms of cyanobacteria poisoning vary depending on the type of toxin ingested and the body system it affects.
Testing and diagnosis
There is no specific test for cyanobacteria poisoning and diagnosis relies on presenting symptoms, history of possible exposure, and ruling out alternative conditions.
Diagnosis involves:
- Physical examination
- Neurological examination
- Blood work
- Urine sampling
- Abdominal ultrasound
Steps to Recovery
Cyanobacteria poisoning ranges from mild to severe; it acts quickly and has no specific treatment.
Mild cases that trigger signs of vomiting and diarrhea may not be identified as cyanobacteria poisoning. These cases usually resolve spontaneously and may not require treatment.
Severe cyanobacteria poisoning is rapidly fatal and can cause sudden death.
Moderate cases of hepatotoxicity (liver poisoning) may result in severe liver damage but some cats may recover.
Since there is no specific antidote, treatment focuses on reducing absorption and treating the symptoms.
Reducing absorption:
- Induction of vomiting
- Gastric lavage
- Feeding activated charcoal
Note: induction of vomiting and/or administration of activated charcoal should only be performed by a veterinarian. There is no safe way to induce vomiting or administer activated charcoal at home.
Supportive treatment:
- Fluid therapy
- Anti-seizure medication
- Liver support supplements
- Treatment of kidney failure
- Topical or oral steroids for skin rashes
Prevention
Prevention relies on avoiding ingestion of or contact with blue-green algae contaminated water. Cats rarely swim or drink standing water, but steps to reduce the risk include limiting hunting behavior, and removing standing water from the garden, such as dirty bird baths or ponds.
Is Blue-Green Algae Poisoning in Cats common?
Cyanobacteria poisoning is rare in cats as they rarely swim, and prefer not to drink standing water. It is more common in hunting cats.
Typical Treatment
- Induction of vomiting
- Gastric lavage
- Feeding activated charcoal
- Fluid therapy
- Anti-seizure medication
- Liver support supplements
- Treatment of kidney failure
- Topical or oral steroids
