Cyanobacteria in Dogs

Cyanobacteria has been responsible for lethal poisonings in humans, animals, birds and fish all over North America and in most countries of the world. In canines, the cyanobacteria are typically ingested through drinking infected water, or through accidental taking on of water while swimming. Not all blue-green algae contain the bacteria, but veterinary professionals advise not to allow your pet in any body of water containing algal bloom, in the chance that it is of a lethal type.

Cyanobacteria causes blue green algae to form in lakes, ponds and other waterways all over the world. This algae overgrowth is called a bloom, and though it may look harmless, cyanobacteria can cause an acute, fatal condition of algal poisoning. The blooms proliferate in hot weather, particularly in late summer and early fall.

Symptoms of a life-threatening reaction to cyanobacteria are many. There are many toxic strains of cyanobacteria that can cause symptoms leading to a fatal conclusion within 30 minutes to 24 hours. If you suspect that your dog may have been poisoned by cyanobacteria, time is of the essence for veterinary care.

• Vomiting
• Diarrhea
• Lethargy
• Depression
• Loss of appetite
• Pale mucous membranes
• Jaundice
• Weakness
• Stumbling
• Muscle tremors
• Rigidity
• Excess salivation
• Algae in vomit or stool
• Blood in urine
• Foaming at the mouth
• Difficulty breathing
• Respiratory paralysis
• Convulsion
• Seizures

Types

Toxic blooms can result from more than 30 species of cyanobacteria, which will produce four types of toxicity.

• Hepatotoxin
• The toxin damages the liver
• Neurotoxin
• The nerve tissues are destroyed by the toxicity
• Nephrotoxin
• The toxin destroys cells of the kidneys
• Dermal toxin
• Reaction to the toxin is in the form of hives or a rash

There are many reasons for the proliferation of bloom, and observations as to how our pets (and us) can be affected.

• High water temperatures (climate change is thought to be a factor) in late summer and early fall allows the cyanobacteria to multiply rapidly
• Winds that push the algae towards the shore and keep it there contribute to the growth
• Unmaintained backyard ponds and stagnant water sources will promote the cyanobacteria progression
• Cyanobacteria thrive in water with a dense surface scum
• Water rich in nitrates, organic nutrients, and phosphates will produce heavy blooms
• Fertilizer runoff and animal waste in the water aids the growth of cyanobacteria
• Blooms can be green, blue, red or brown
• Dry algae material can be found on the shoreline
• Dogs are the domestic animal most susceptible to cyanobacteria because they love to swim and drink from lakes and ponds, and will enter the water no matter what the smell or appearance
• Our canine companions will ingest the water, inhale in error when swimming, and lick the scum off their fur when they get out

The rapid onset of signs of cyanobacteria illness does not leave much time for determining the diagnosis. Inform your veterinarian immediately of your suspicions, and describe the appearance of the waterway that your furry family member was swimming in, or drinking from. Chances are, your veterinary caregiver may see a greenish stain around your pet’s mouth, nose, legs, and feet which will verify the exposure to the cyanobacteria. If possible, bring a sample to the veterinarian for analysis.

A complete blood count and serum chemistry panel could show the presence of alkaline phosphatase and bile acids. Evidence of hepatitis and severe coagulopathy may be seen as well. The feces, upon study, could show cyanobacterial biotoxins.

Treatment will depend on how the cyanobacterial poisoning symptoms have advanced. If your pet is severely ill, sometimes euthanasia is the only option.

However, if you are fortunate in that you and your beloved pet have arrived at the clinic soon enough, intensive care and aggressive treatment may save your dog. Although not always successful, and often difficult, recovery is possible.

Your dog will be admitted to the hospital, and a treatment protocol will begin. Treatment will include the following as needed, depending upon the type of cyanobacteria involved.

• Intravenous with electrolytes
• Seizure medicine
• Oxygen therapy
• Mucosal protectants
• Vitamins
• Antibiotics
• Nutritional supplements
• Medication to bind bile acids
• Drugs to remove toxins from the gastrointestinal tract
• Sometimes activated charcoal is used

The length of hospital stay and recovery time will depend on how ill your dog was upon arrival, his age, his medical history, what type of toxicity was present, and his response to therapy. Every pet is different and has an individual reaction to treatment.

Recovery is possible, but may take weeks or months. Keep in close contact with the veterinary team and advise them often on your pet’s progress. In the meantime, prevent exposure to your pet by not allowing him in the water where the incident took place, including nearby waterways. Inform your local water officials about the toxicity. Your veterinarian will be able to provide backup information if requested by the authorities.

Dogs who do recover from cyanobacteria will usually have lingering liver damage, as well as other possible complications but with your care, and the support of your veterinary team, your canine companion can have a good quality of life. Your veterinarian can advise on diet, exercise, and aids such as B vitamin supplementation (to aid the liver).

Scientists are working on better testing methods for more quickly identifying toxins in the water and toxicity to pets who have been exposed.