Blue Green Algae Poisoning in Dogs

  • Blue green algae is often found in stagnant water such as lakes and ponds.

  • Blue green algae is dangerous due to the toxins which can cause organ damage. 

  • Blue green algae can be very difficult to see grossly.

  • Blue green algae grows best when the weather is more warm, so exposure is most common between late spring and autumn.

  • Contact your vet ASAP if you think your dog has been exposed to blue green algae.

  • Animals are at risk if they swim in or drink from water containing blue green algae.


Symptoms of blue green algae poisoning are generally none specific and can develop and can develop from minutes to hours. Contact your veterinarian immediately if you have any suspicion your dog has had access to blue green algae.


Symptoms Include:


  • Weakness

  • Lethargy

  • Lack of appetite

  • Breathing difficulties

  • Vomiting or excessive salivation 

  • Increased thirst

  • Diarrhoea (dark, tarry stool)

  • Bleeding

  • Pale gums

  • Jaundice (yellow tint to gums and skin)

  • Shock

  • Seizures

  • Collapse and coma

  • Death


Treatment for blue green algae toxicity is supportive, your vet will try to prevent the toxins causing any more damage and treat any symptoms they are displaying. 

Your vet may give charcoal, wash your dog to prevent any further ingestion and if indicated begin treatment with fluids, medical treatment and monitoring changes in their blood parameters.

Outlook for blue green algae poisoning is generally guarded, the toxins work very quickly. The sooner veterinary advise is sought, the better the prognosis.


Avoiding Blue Green Algae


  • Avoid stagnant water 

  • Always check water before allowing your dog in and do not allow them to drink from open water

  • Local councils can give you advise on blue green algae in water sources in that area


Humans can also be affected by blue green algae, if you have any concerns about exposure to blue green algae then always contact the NHS or your doctor for advice.

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This advice is for UK pets only.Written by vets. Please always seek advice from your own veterinary surgeon if you have concerns about your animal, never try to treat an animal yourself or give any medication without veterinary supervision.

Lily Pond