Don’t Let Your Dog Swim in Green Water
If your pup loves to swim and splash around in ponds, pay attention if one of your favorite watering holes suddenly turns green or smells funny. During this time of year, microscopic creatures called cyanobacteria can “bloom”, sometimes creating chemicals that are toxic to animals and humans.
This is more dangerous for dogs than for people, because few people will see a dirty, smelly lake and decide to jump right into it (or, for that matter, eat the dead fish they find there). Toxins are most dangerous if swallowed, so if your puppy swallows pond water or licks his fur after leaving the pond, he may ingest the toxins.
Where does cyanobacteria bloom?
Blooms have occurred in all 50 states and Puerto Rico, according to the Centers for Disease Control and Prevention. They form in warm, slow-moving water, so think of ponds and swamps, not raging rivers. Flowering occurs when microscopic creatures receive a flood of nutrients from the surrounding area, so runoff from sources such as farms and overflowing septic tanks tend to play a role.
Incidentally, there are other types of blooms , including those caused by dinoflagellates and diatoms, and these can also be toxic. Cyanobacteria blooms most often occur in fresh water, but there may be toxic blooms in salt and brackish water.
(Botanical fact: Cyanobacteria used to be called “blue-green algae” because they photosynthesize and are microscopic, like algae. But algae are technically plants, while cyanobacteria are not.)
How do you know if water is toxic?
It’s not as easy as checking the color, although the appearance of the water can be a big clue (especially if the water is normally clear but has recently changed). The CDC advises looking for suds, suds, or seaweed mats, and some flowers that look like spilled paint. They also come in other colors including blue, red and brown. And sometimes the water will smell like gasoline or rotten eggs.
However, sometimes toxic blooms are not apparent, especially if the algae have matted below the surface. Pay attention to warnings that may come from the local health department or that may be posted near lakes. California publishes known algal bloom locations on a map on its Harmful Algal Bloom Portal .
What happens if my dog takes a dip in the water?
First, get them out of the lake and take a shower. This also applies to people. You can get harm from skin contact with toxins or even from inhaling the smallest droplets of water. Pets can also lick their fur or pick up objects (like a leash) that get wet in water, so wash it off as soon as possible.
If you are concerned that your pet may have ingested toxic water but has not yet shown symptoms, consider calling your veterinarian or the ASPCA Pet Poison Control hotline at (888) 426-4435. (This is a paid service; your veterinarian can answer questions for free.) Help for people is available through the regular poison control hotline at 1-800-222-1222 or on their website . If you or your pet already has symptoms, skip the hotline and just seek medical attention.
You and your pet may experience vomiting and diarrhea, and watch especially for neurological symptoms such as dizziness, weakness, or stumbling. Pets may also experience excessive salivation and seizures. (If you were in the water too, you might notice a headache or stomachache, and you should take care of yourself.)
If you notice any of these signs, contact your veterinarian immediately and be sure to mention your pet’s recent bath. Here is a CDC guide for veterinarians , which notes that there are no tests or universal treatments for cyanobacteria poisoning. However, activated charcoal can help if given right away, and in cases where a veterinarian can figure out which particular toxin was involved, there are medications that can help.