Animal Health & Welfare: Swimming and Water Issues For Your Pet

  Rex loves to swim. We were at one of his favorite spots, Navarro River Campground, when I noticed the large amount of green ‘mats’ along the shoreline (exposed due to the low water level). It was blue, and it was green—is this the blue-green algae that can be toxic to animals? 

     Reports of dog deaths after swimming in water with a cyanobacteria algal bloom have increased over the last few years, and have been reported as nearby as the Russian River, the Eel River and Clear Lake. Higher temperatures (over 77 degrees), low water levels, long sunny days and high nutrient levels (of phosphorus and nitrogen) can contribute to cyanobacteria, creating a toxic ‘bloom’. Dogs tend to ingest water while they swim, or they may lick the water off their coats after swimming. Symptoms can occur within minutes—from vomiting and skin irritation to foaming at the mouth, seizure . . . and even death. 

     So what do we look for? How can we tell? Is it harmless seaweed or toxic blue-green algae? When conditions come together and create a toxic bloom, it can have a bright green ‘pea soup’ (above) or a ‘brown jelly’ appearance. Brown ‘scum’ or foam (below)on the surface of the water and along the shoreline can be formed by the blue-green algae bacteria. There also tends to be an ‘earthy’ or ‘loamy’ smell that comes with a cyanobacteria algal bloom. Typically in fresh water ponds and lakes, blooms can also occur in rivers with very slow moving water. 

     The best preventive measure is simply not allowing animals to drink or swim in water that is of concern. Not all algae blooms produce the harmful toxins (microcystins and anatoxins). Water needs to be tested to determine if it is, in fact, toxic. Suspicious bodies of water can be reported to the Mendocino County Health and Human Services Agency—Environmental Health at (707) 234-6625.