Toxic Blue-Green Algae - Keeping Your Dog Safe in the Water

If your dog swims in or drinks from streams, lakes, ponds and other natural water sources you need to be aware of potentially toxic blue-green algae. This article will give you some tips on how to spot it, symptoms to look out for and practical ways to keep your dog safe.

Keep your dog safe by learning to spot toxic blue-green algae

What is blue-green algae?

Blue-green algae isn't really algae at all - it's a bacteria called Cyanobacteria. When conditions are right it multiplies rapidly and ‘blooms', clumping together in a way that looks like algae – hence the name.

Some blue-green algae produces harmful toxins which can cause fatal liver failure in dogs when ingested. Whilst some types are more toxic than others, it's impossible to tell the difference between them without laboratory testing. It's safest to consider all blue-green algae a hazard.

How to spot blue-green algae?

Blue-green algae tends to develop in still or slow moving water particularly in summer when it's been hot and dry. Unfortunately that's the same time that dogs are most likely to be drinking more or taking a dip to cool off.

It's impossible to tell just by looking whether a particular algae bloom is the toxic kind. That means it's important to stay away from anything that looks suspicious. That includes any water that:

  • looks like pea soup
  • has foam or scum on the surface
  • contains flakes, fuzzy clumps or dots of green-blue-brown
  • leaves a slimy green residue on the surrounding ground or anything dipped in it
  • has dead fish or other creatures in it
  • smells bad

Blue-green algae often gathers around the water's edge so make sure to check the shallow places your dog will want to drink from. Although it's called blue-green algae it can be any shade of green through blue and sometimes more brown-red coloured too.

Scum from blue-green algae can be poisonous to dogs
Blue-green algae can leave a slimey residue

Note: Blue-green algae can grow in any water. That includes your garden pond, buckets and plant saucers left to stagnate. Refresh standing water regularly and use circulation pumps to keep water in ponds moving.

Practical Tips to keep your dog safe

Playing in water is one of the most fun parts of summer. You don't have to stop your dog going near water completely, just take precautions to minimise the risk. That includes:

  • Keeping away from areas you know have or are prone to blue-green algae
  • Checking local environment health bulletins, news or social media groups for notices about local water ways
  • Look for warning signs posted near the water or on notice boards in car parks – avoid any water with a warning sign even if it looks clear
  • Have your dog on lead with you approach water so you can assess it before your dog jumps in – what was safe last visit might not be this time
  • Take clean drinking water with you for your dog so they are less inclined to drink from ponds/lakes or puddles
  • Rinse your dog after swimming so they don't lick their fur

Symptoms of Blue-Green Algae Poisoning

If your dog becomes ill after drinking or being in the water or your dog accidently comes into contact with water you think may be a risk treat it as an emergency and call your vet immediately and explain your concerns.

Symptoms may take minutes or hours to develop, depending on the type of bacteria, and include:

  • Disorientation/confusion
  • Drooling
  • Breathing difficulties
  • Being sick
  • Diarrhoea
  • Fits or seizures
  • Weakness/collapse

The quicker you get your dog to a vet for treatment the better the prognosis for recovery.

Report It

If you think you've spotted blue-green algae (and there aren't already warning signs) you can report it to the landowner or the Environment Agency who can investigate: Report an Algae Bloom

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