Giardia in Dogs

Giardia is a parasite that can afflict dogs, cats and humans with the infection Giardiasis. In this post, our Westport vets define Giardia, how it spreads, and how it is treated. 


What is dog Giardia?

Giardiasis is an infection of the intestines that can occur in both people and animals. This infection is caused by the Giardia parasite, of which there are 8 different genotypes labeled A through H. 

Types C and D most commonly infect dogs, while F is the most common culprit in cats. For humans, it's types A and B. 

While Giardia in dogs does not always cause problems, but when issues do occur they are highly unpleasant. The most common symptom is diarrhea. Giardiasis is particularly dangerous for puppies, dogs with compromised immune systems and senior dogs. 

Giardia in Dogs, Westport Vets

What are the signs of Giardia infection?

If your dog is showing concerning symptoms of illness, your best bet is to book an appointment with your vet, since many of the signs below are common to a number of conditions. that said, owners can be on the look out for several symptoms of Giardia, including:

  • Diarrhea 
  • Vomiting
  • Failure to gain weight 
  • Weight loss
  • Dehydration 
  • Poor coat appearance 

Diarrhea and weight loss often happen when the parasite disrupts a dog's internal systems, inhibiting their ability to absorb water, electrolytes, and nutrients. The diarrhea might be continual or intermittent, especially in puppies. If the disease is not diagnosed and treated, severe weight loss and even death can occur. 

How are dogs infected with Giardia?

This single-celled parasite lives in the intestines of mammals, birds and amphibians and as mentioned above, has different subspecies. While each subspecies targets a specific group of animals, all have the same lifecycle and method of transmission. 

There are two stages of Giardia's lifecycle. Mature parasites (trophozoites) live in the small intestine, multiply and become cysts. Cysts are then infective and shed via feces from an infected animal. They can survive for weeks in the environment as cysts until being ingested by another animal. They then transform into trophozoites and repeat the lifecycle. 

Dogs can contract Giardia by drinking water or eating grass or other substances that have been contaminated with feces. Any seasoned pet owners know our dogs explore the world using their mouths. This makes the parasite easy to pick up in an environment by doing anything from drinking from a puddle, eating another animal's poop or chewing on a stick. 

Our four-legged companions can also spread the parasite, even if they do not show signs of infection. As you can imagine, this is concerning, especially if you live with more than one pet. While the parasite is unlikely to be transmitted between dogs and cats, transmission from dog to dog is very much a concern. If one of your pets is diagnosed with Giardia, ask your vet which precautions you should take with your other pets. 

Can dogs pass Giardia to people?

Fortunately, the risk of humans contracting Giardia from dogs is relatively low, but it can happen. Make sure to wash your hands after handling your dog's poop to reduce this low risk. 

In humans, giardia transmission commonly occurs via drinking water, not from pets. Giardiasis in people is known as "Beaver Fever." Consider buying a water filter if your water source is known to contain the parasite, and avoid drinking contaminated water especially while traveling. This parasite can also be present in soil and on food, so wash all produce before eating and wash your hands after working with dirt. 

How is Giardia treated?

If you've noticed your dog is suffering from diarrhea or other symptoms, call your vet right away. Your vet will likely perform several diagnostic tests to find out whether your dog has Giardia. Depending on the results and the severity of your dog's case, a treatment plan tailored to your dog's needs can be developed. 

How can I prevent my dog from getting re-infected with Giardia, or making my other pets sick, during treatment?

As you've read here, Giardia is a highly unpleasant parasite that can't be prevented with the tick, flea and heartworm preventatives your dog would regularly receive from a vet. However, there are steps you can take to prevent your dog from contracting Giardia. One of the most important items on the list is to ensure your dog as access to clean, fresh water at all times to cut the risk of them drinking from infected puddles (this will also contribute to your dog's overall health). If you need to, boil your dog's water (then let it cool before offering it to your dog) or purchase a filter that has been proven to remove Giardia cysts if you live in a place where Giardia is present. 

Along with washing your hands after handling dog poop and quickly disposing of it, you should inform your vet if you have other animals in the house, even if they are not showing any symptoms. Your vet may want to start your other animals on medication as giardiasis is often asymptomatic and other pets could still be spreading the illness. 

All household animals should be bathed regularly to remove cysts from the hair coat. You should also be sure to disinfect your pets' environment (crates, beds, etc.) and wash their water and food bowls daily. 

Cleaning should take place until at least a few days after all pets in the household have completed their medication. 

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.

Is your dog displaying signs of giardiasis? Contact Poster Veterinary Associates to schedule an appointment and ensure your dog is protected. 

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