Protozoa, Bacteria and Algae, Oh My!

Many people have been asking about the safety/health issues with letting their dogs swim in ponds and other public water areas. There are a number of parasites, bacteria and algae that can harm our pets.

The first and foremost of these is Giardia. Giardia is a protozoal (meaning they can swim) parasite that causes a really bad diarrhea. It can be found in standing water such as puddles and ponds. Giardia can also be caught from eating poop that is infected (Butt sniffing/licking is a way this happens).

Giardia has 2 stages: cyst and trophozoite. The cyst stage is what your dog picks up, basically a package of 2 little Giardia waiting for a good environment to wake up and reproduce in. The cysts can survive in moist environments for a very long time. After your dog ingests the cysts, they travel to the intestines where they break out of the cyst and go into the trophozoite stage. This is when they multiply faster than teenage bunny rabbits and cause your dog to have really yucky diarrhea. The cysts can survive in moist environments for a very long time.

At this point, usually you take your dog to the vet because you are tired of cleaning up nasty poop. (Be prepared to bring a sample of the stool for the vet appointment - make sure it is something less than 24 hours old and has not been frozen) Your vet will do a complete physical and will have the Technician do a few tests on the poop to check for parasites- usually a fecal float (will check for the usual parasites - sometimes they can see the trophozoites or cysts of Giardia but they are very tiny so they usually aren't seen on this test), and if your vet has the test kit, they can do a special test for Giardia. Make sure to tell your vet if your dog has been in areas of standing water or has been swimming in ponds. This will help him to choose the best tests and treatments for your dog.

If your dog tests positive for Giardia, he/she will be given medicine to treat the problem. The medicines are typically Metronidazole (name brand is Flagyl) or Fenbendazole (name brand is Panacur). If you own more than one pet, make sure to tell your vet this as well. Sometimes he will treat all the dogs in the household at the same time. Keeping your dog's enviroment clean will help keep Giardia from reappearing in your dog. Make sure to wear gloves and wash your hands after cleaning up the yard -- People can get Giardia too!

Dogs can get bacteria such as E. coli from swimming in infected water. E. coli is a bacteria that normally occurs in many animals' stool. When dogs swim in water and poop, E. coli is present. If enough dogs poop in the water, others can become infected. Again this causes a yucky diarrhea. Vets typically use antibiotics to treat this bacteria.

There has been talk of a blue-green algae that dogs can ingest while swimming in algae-infested ponds. This blue-green algae can be toxic when it is ingested in large amounts and dogs can become really sick or can die. It is not very common, but is it dangerous.

So, what should you do? Keep your water loving retriever out of all but the backyard swimming pool? Discourage your dog from drinking in puddles at the park? No, but you should use some common sense. Don't let your dog swim in areas where other dogs poop and the water is untreated. Even if the water is treated, keep your eyes out for signs of diarrhea and call your vet as soon as the problem arises. Pick up your dog's waste, even if you are in the park and no one is around to see you pick it up. Keeping dog waste from entering the water supply will do a lot to keep other animals and people healthy.

This is not an exhaustive list of problems associated with water and dogs, but Giardia is very common. A recent Idexx (veterinary laboratory) study showed that about 11% of dogs with diarrhea or other gastrointestinal problems test positive for Giardia.

If you have questions about these problems or are concerned about letting your dog swim in ponds, call your vet and ask him his recommendations.

See you at the park!