Lead: When blue-green algae (cyanobacteria) blooms, the water surface looks like paint. Contact can kill a dog within hours. In summer heat, Wivenhoe, Somerset, North Pine and still reaches of the Brisbane River are high-risk. Here is how to spot it and what to do.
What is blue-green algae?
Despite the name, it is a group of bacteria that produce liver and neurotoxins. Warm, still, nutrient-rich water (dams, backwaters, lakes) blooms in summer. Toxins survive boiling.
How to identify
- Blue-green, yellow-green or reddish-brown surface scum, like paint spilled on the water
- Sweet, musty odour
- Dried greenish powder on the bank
If you see any of these, pull your dog away immediately.
Known SEQ hotspots
- Lake Wivenhoe, Lake Somerset
- North Pine Dam (Petrie)
- Still backwaters of the Brisbane River (away from main flow)
- Golf course water hazards
The Queensland Department of Environment publishes weekly algae monitoring — check qld.gov.au/environment/water before heading out.
Signs of poisoning
- Vomiting, drooling
- Weakness, unsteady walking
- Skin redness or itching on contact areas
- Seizures, collapse
First aid
- Rinse the dog mouth, skin and paws with clean water immediately
- Stop them grooming — toxins are ingested again through licking
- Go straight to an emergency vet; bring a water sample or photo to help diagnosis
Summer rule of thumb: Let dogs swim only in moving, approved swimming areas. No drinking or swimming in dams, stagnant pools or irrigation channels.