My niece rescued a puppy recently. This poor little thing has suffered from two bouts of giardiasis in the short time she’s had her. My niece’s puppy got me thinking about my experiences with dogs and giardia. And wow! Is it unpleasant!
Giardiasis is an illness you probably haven’t heard of unless either you or your dog has experienced it. That’s right… people can get it too. In fact, it’s the most common intestinal parasite in humans.
What is it?
In dogs, giardiasis can be completely repulsive or it can go absolutely unnoticed. It’s an illness caused by a single-celled parasite called giardia that infects the gastrointestinal tract.
Giardia is not a worm, bacteria or virus. It’s a parasite.
This parasite can cause diarrhea, vomiting, weight loss and lethargy. But some dogs show no symptoms at all.
There are 7 different types of giardia that affect dogs, cats and humans. They’re labeled A through G. Dogs usually get C and D, but can get A and B which are the strains humans get. Cats are usually infected with F.
When people get “travelers diarrhea”, it’s caused by giardia. They’ve likely consumed water contaminated by the parasite. This is not uncommon in some countries.
Giardia goes through two phases. The first is the fragile form when it’s growing and feeding on the gut. Then it matures, and it’s encapsulated in microscopic cysts (sacs) that come out in your dog’s poop. These cysts are very hardy and can survive for several months in the right environment—water and dampness.
How do dogs get it?
Dogs are infected when they consume anything with contaminated feces on it; another dog’s poop, a stick, a toy, grass, water.
When the dog swallows the cysts, they pass into the intestines and go through a transformation into a trophozoite, the growing feeding form. They feed off the intestinal wall. They reproduce by dividing and some become cysts. Those cysts eventually pass in the stool about 5 to 12 days from ingestion.
This is a parasite you’ll find any time of the year, anywhere in the U.S. and around the world.
What are the signs?
Some times a dog will be a carrier of giardia and will be asymptomatic, perhaps for many years. Then, without warning, after years of undiagnosed giardia your dog may have a sudden bout of bloody diarrhea.
But usually a dog with this parasite has symptoms. Their diarrhea may be bloody, greasy, frothy, mucousy and very smelly. They may have diarrhea continuously or intermittently.
Your dog may also vomit, seem lethargic and suddenly lose weight.
This parasite causes many gastrointestinal disturbances in dogs.
How is it diagnosed and treated?
If you suspect your dog has giardia, call your vet. If left untreated, severe diarrhea can be fatal, especially in puppies, senior dogs, and dogs with health problems.
Your vet will need a fresh stool sample. They’ll do one of two tests: The fecal float test or the fecal ELISA test. The float test checks for evidence of giardia cysts in the stool sample. Whereas the ELISA test checks for giardia antigens in the dog’s body.
The float test isn’t very accurate. An infected dog will shed cysts intermittently from their GI tract, making it possible to get a stool sample with no cysts in it.
As a result, false negatives are common with the float test. Doing the fecal float test 3 times over the course of 5 days can improve the likelihood of detection though.
The ELISA test is more accurate but your vet will need to send the stool sample out to a lab. It isn’t usually done in the office. So you’d have to wait for the results.
If your dog tests positive, your vet will prescribe one of two drugs, maybe both. Fenbendazole or metronidazole for 3 to 10 days is the usual treatment. How long and which drug depends on your dog’s case.
Your vet may recommend a low-residue highly digestible diet like Husse to lessen the diarrhea during treatment.
Bathe your dog on the last day of treatment to remove any giardia that may be on their coat, especially around the hindquarters. Start from your dog’s head and work towards their rear end. After washing their behind, don’t touch the areas you’ve already cleaned.
Disinfect your dog’s bowls and toys in boiling water or the sanitize cycle in your dishwasher.
Steam clean upholstery and carpeting, and wash bedding on the sanitize cycle in your washing machine.
Disinfect hard surfaces with a bleach solution or a household cleaner made for disinfection.
Depending on the severity of your dog’s case and their overall health, they may need other tests, treatments, and follow-up. But 2 to 4 weeks after your dog finishes treatment your vet will want to run another fecal test to be sure the giardia is gone.
If your dog has recurring giardia, consider whether the parasite is still living in their environment. If other dogs or cats live in the house, you may need to treat them as well.
Dirt and grass can harbor giardia for months. Spray diluted bleach on the areas where they’ve pooped. If you walk your dog in your neighborhood, take a spray bottle with you to spray the area after you’ve picked up their poop.
Are there serious risks?
Most healthy dogs recover from giardiasis with no complications. But older sick dogs or dogs with compromised immune systems are at risk for complications including death.
In addition, people with compromised immune systems are at risk of getting giardia from a dog. You can’t be certain which strain your dog has. They can have A or B.
So if someone in your home has cancer, AIDS, is very old or very young, they should take precautions. And use extreme caution when handling poop or giving the dog medicine. Wash hands thoroughly after doing so.
Can it be prevented?
You can minimize your dog’s exposure to giardia by limiting their time at dog parks, kennels, doggy day care and the groomers.
Don’t let your dog drink from communal water bowls at the pet store, the dog park, or any other place in your community.
They should never drink from puddles, lakes, ponds or streams. Feces from other animals may contaminate them.
Never let your dog eat another dog’s poop, or their own (that’s a topic for another day).
If you live in a place where giardia is in the drinking water, buy a filter meant specifically for getting rid of this parasite. Or boil your water. And always let the water cool before giving it to your dog to drink.
But despite your best efforts, your dog may get giardia. It’s common in rescue dogs. It’s common when dogs come from breeders with lots of other dogs. It’s common when dogs are with other dogs regularly.
The best you can do is treat giardiasis proactively if it happens to your dog… and have a lot of paper towels and Nature’s Miracle on hand.
Has your dog had giardiasis? What were their symptoms? Share in the comment section at the top of the page.