Blue-green algae poisoning
Many dogs enjoy a swim or paddle on a hot day, but care must be taken to avoid areas with blue-green algae. Blue-green algae appear in many bodies of water, and its blooms appear as green or greeny-brown scum on the water surface. These blooms contain organisms which can produce toxins under certain conditions. These toxins can cause severe illness and even death in dogs, and so care must be taken to prevent dogs swimming or ingesting water in affected areas.