Is your pet safe to swim in our local rivers?

Unfortunately, many waterways have toxic algae (cyanobacteria) lingering. It is important to actively consider if your favourite swimming spot is a safe place to be by looking for signs of the blue-green algae in the water and you can also refer to www.lawa.org.nz/swim before setting out. Freshwater toxic algae, known scientifically as cyanobacteria, can be deadly to dogs and even people.

What should we look for?

If you notice musty smelling, black slimy mat-like growths on the river bed stones during low river flows, it is safest for you and your dog to avoid these areas and look for more mobile sandy beds.

• Is there any signage indicating the level of risk from toxic algae?
• Are the river levels low?
• Can you see black slimy mat-like growths on the river bed stones?
• Does the slime smell earthy and musty?
• Are there scums of algae along the shoreline?

Dogs are particularly at risk from blue-green algae and it isn’t uncommon for them to suddenly pass away after ingesting the algae. We aren’t completely sure if this is because they are particularly sensitive to the toxins compared to other animals, or if it is because they are more likely to eat the algae. Dogs are known to eat things that are smelly and decaying, so it isn’t particularly surprising. It can also be a risk to small children playing on the shorelines that may grab some and eat it quickly before adults can stop them. Even swimming in water with the algae can cause sickness.

The algae produce toxins that can cause a variety of symptoms after ingestion but the common form we see causes muscle contraction which can lead to respiratory arrest and ultimately death. The outcome depends on the amount ingested but 1 tablespoon can cause the demise of a dog or small child. Sometimes the dogs collapse at the river and other times they become symptomatic upon arriving back at home. Other symptoms that may be seen in dogs are, paralysis, excessive frothing at the mouth, lethargy, diarrhoea, fast shallow breathing, muscle tremors or convulsions.

Currently there are warnings that some rivers are unsafe in the region so our advice is not to let your dog roam freely – especially in low flow areas. If you suspect your dog has swallowed contaminated water or eaten algae, please contact the closest veterinarian immediately for advice. If your animal is showing symptoms of poisoning it will require aggressive treatment and needs to see a veterinarian as soon as possible.