Giardia in Dogs
Written by Small Door's medical experts
Giardia in dogs can be contagious to humans and other household pets. After the initial infection, giardia can quickly spread in situations where dogs are living together in large numbers, like animal shelters and kennels. Knowing the symptoms and understanding the risks will help you get your dog back to health and prevent the spread of this unpleasant disease.
In This Article
Giardia is a protozoan parasite (a single-celled micro-organism) that causes intestinal infection. The technical term for this infection in dogs is “canine giardiasis.” While rarely fatal, giardia can cause discomfort for you and your dog.
Dogs with giardia frequently don’t exhibit any symptoms and the giardia is only discovered through testing of the dog’s stool. Because giardia lives in the intestine, most of the symptoms are related to defecation.
Symptoms of giardia in dogs can include:
Acute diarrhea (very watery diarrhea)
Mucus and red blood in diarrhea
Giardia is usually associated with diarrhea, as it is the most common clinical symptom of giardia infection, and infected dogs can produce large amounts of watery feces. Less common symptoms include decreased appetite, abdominal discomfort, and vomiting. In rare cases, dogs may strain to defecate and even pass red blood and mucus in their stool. However, most dogs infected will be asymptomatic, which means they will show no signs of the disease but can pass it on to other animals.
What does giardia poop look like in dogs?
Giardia cysts are microscopic and are too small to be observed with the naked eye. Because giardiasis often causes diarrhea, the presence of soft, watery, greasy, or greenish-colored feces could be an indicator that your dog has giardia. However, as these may also be symptoms of other conditions, it’s always best to get your veterinarian to confirm the diagnosis.
Dogs contract giardia via ingestion. This includes eating, licking, or sniffing objects that have giardia cysts on them. The most common route is by drinking contaminated water. Giardia is found all over the world, transmitted by what medical professionals call the fecal-oral route, which means the parasite is passed through one animal’s feces into the environment, where another animal ingests it. The prevalence of giardia among mammals makes it common in streams, ponds, puddles, and other bodies of still water.
Drinking contaminated water
Licking contaminated surfaces
Eating contaminated food
Consuming contaminated feces
Sniffing giardia cysts in feces or on any surface
Being in close proximity to other animals that have giardia
There are two stages of the life cycle of giardia: cysts and trophozoites. Trophozoites, the active feeding stage, attach to the host’s small intestine to feed and multiply. They then encyst, and these cysts are passed in the feces of infected animals. Sometimes, these feces end up in bodies of water. Giardia in humans got the nickname “beaver fever” after a group of hikers drank from water that had been contaminated with giardia from the resident beavers. Once in the environment, giardia cysts are then consumed by new hosts.
Cysts can survive for weeks in the environment. They are quite resistant, which means as an infected animal passes more cysts, the number of cysts in the environment increases.
Giardia in puppies
Giardia is more serious for dogs with underlying conditions, elderly dogs and puppies. Giardia-induced diarrhea causes your puppy to excrete water, salt, and vitamins before they can be absorbed, meaning they can become dangerously dehydrated. Puppies may contract giardia by interacting with infected-surfaces, their parents, or other members of their litter. Thankfully, they can be treated and cured of giardia in the same way as adult dogs.
A giardia infection is confirmed through fecal testing. Diarrhea is a common symptom of many diseases and conditions, and alone doesn’t indicate giardiasis. Your veterinarian will ask you for a history of your dog’s symptoms and behavior. They may also perform other diagnostic tests to rule out potentially dangerous conditions like toxicity and the parvovirus.
Both cysts and trophozoites pass in the feces of infected dogs. While only the cysts can infect other animals, cysts and trophozoites can help veterinarians identify giardia under a microscope.
Several types of tests can be done to diagnose giardia in dogs. Sometimes, parasites show up on simple saline smears. However, veterinarians may recommend special fecal tests or even antigen tests that look for parasitic protein in your dog’s feces. These tests may need to be repeated multiple times. Cysts shed intermittently, and so it is often crucial to perform repeat testing over a period of days for accurate diagnosis.
A combination of medication and environmental management will treat giardia. The most common medicine used to treat giardia in dogs is the deworming agent fenbendazole (Panacur). Additionally, a combination of other medications, like pyrantel and febantel, are available. Metronidazole (Flagyl) is also frequently used to treat giardia. Since giardia can be difficult to get rid of, some veterinarians prefer to treat with fenbendazole and metronidazole simultaneously.
Medications can control parasites within your dog’s body, but recovery depends upon your dog’s immune response. Healthy dogs stand a better chance of a swift recovery than dogs with compromised immune systems or additional infections. Some strands of giardia may also be more aggressive than others, which can prolong recovery. Bathing your dog regularly throughout the infection can help remove cysts from their coat. It reduces the risk of reinfection and lowers your risk of contracting the disease from your dog.
What is the Prognosis for Dogs with Giardia?
Giardia is easily treatable, and infection is rarely life-threatening. However, for elderly dogs, puppies, or dogs with immunodeficiencies, the risk of complications and even death is possible. After your dog’s treatment is completed, they should be retested within two to four weeks to ensure the infection is completely gone.
Yes. With medication and proper management, your dog can be cured of giardia. However, because giardia is prevalent in most environments, there is a risk of reinfection.
Is giardia in dogs contagious for humans and other pets?
Yes, giardia can be contagious for humans and other pets. Giardia can easily be transmitted from dog to dog, and in some cases from dog to human. There are several different species of giardia. Some are contagious to people as well as an array of mammals.
If your dog is diagnosed with giardia, practice good hygiene habits like washing your hands before eating and after cleaning up dog poop. Disinfecting home surfaces with common disinfectant sprays like Lysol (or any disinfectant that contains bleach) will destroy the cysts and is essential to use on food preparation surfaces.
Giardia cysts thrive in wet, damp environments, so keeping these disinfected areas dry afterwards is essential. After you’ve cleaned your pet’s sleeping area, relocate your pet to another part of your home for several days. Relocating your pet will prevent reinfection, and allow enough time for any giardia that survived the disinfectant to die.
What is the cost of treating giardia in dogs?
Giardia is a relatively inexpensive disease to treat on its own. It does not require surgery or expensive medications.
Expect to pay for your dog’s medication, veterinary office visits, and any additional tests. The cost varies depending on location, severity, and whether your dog needs to visit the veterinary emergency room.
Managing giardia can be frustrating, as reinfection is common. That’s because animals are often repeatedly exposed to the parasite once an environment has been contaminated. However, there are steps to avoid this continued exposure.
Cleaning up feces immediately from kennels and indoor runs can prevent infection. Washing these areas with an appropriate disinfectant spray further reduces the risk of infection.
Some of the areas your dog visits are too large to be disinfected. Avoid bringing dogs into potentially contaminated outdoor areas for at least a month. This gives the parasite time to decay and die. If you have followed these recommendations and your dog continues to show signs of giardia, you may need to repeat the treatment or try a new medication. You may also need to treat other animals in the household, as some may be shedding cysts without showing symptoms.
Giardia can’t always be prevented, but you can reduce your dog’s risk of contracting the parasite.
Prevent your dog from drinking from sources of stagnant water. Streams, puddles, and lakes often contain giardia. Wildlife feces are another source. Prevent your dog from consuming potentially contaminated substances by keeping them leashed, and make sure they always have access to clean, fresh water.
If you and your dog travel to places with high incidences of giardia, consider giving your dog filtered or bottled water. This will reduce the risk of infection from their drinking water and prevent the potential spread to human members of your family.
Is there a vaccine for giardia in dogs?
No, there is no vaccine for giardia. While the parasite is common, it is not as prevalent as other intestinal parasites. Therefore, dogs are not routinely treated with deworming medications for giardia.
Giardia is a single-celled parasite that causes intestinal issues such as diarrhea, and is highly contagious for other pets and humans. Providing your dog with access to clean, fresh water and restricting their ability to drink stagnant water or consume contaminated material will reduce their risk of infection. Giardia can be treated and is rarely life-threatening.