Giardia is a microscopic parasite that causes the diarrheal illness known as giardiasis. Giardia (also known as Giardia intestinalis, Giardia lamblia, or Giardia duodenalis) is found on surfaces or in soil, food, or water that has been contaminated with feces (poop) from infected humans or animals.

Giardia is protected by an outer shell that allows it to survive outside the body for long periods of time and makes it tolerant to chlorine disinfection. While the parasite can be spread in different ways, water (drinking water and recreational water) is the most common method of transmission.

Giardia intestinalis (aka: G.duodenalis, G.lamblia) is a common, microscopic (intestinal) parasite that commonly affects humans, dogs, and cats.

Common signs and symptoms of Giardia infection (in both humans and pets) are diarrhea, gas, abdominal discomfort, nausea, and vomiting. However, it is possible to be infected and have no signs or symptoms of illness.

How is Giardia spread?

Anything that comes into contact with feces (poop) from infected humans or animals can become contaminated with the Giardia parasite. People and animals become infected when they swallow the parasite. It is not possible to become infected through contact with blood.

How does my dog or cat get infected with Giardia?

Your dog or cat might get infected by:

Young pets, like puppies and kittens, have a higher risk of infection than adult dogs and cats.

How do I protect myself if my dog or cat has a Giardia infection?

The risk of acquiring Giardia infection from your dog or cat is small. However, there are some steps you can take to minimize your exposure to Giardia if you have dogs or cats:

If my pet has a Giardia infection, how do I clean and disinfect my house?

Giardia is hard to completely eliminate from the environment, but there are things you can do to decrease the risk of your pets’ reinfection and of human infection.

How do I reduce the amount of Giardia in my yard or outdoor environment?

Giardia is hard to completely eliminate from the environment, but there are things you can do to help decrease the risk of pet reinfection and of human infection. Please remember that despite your best efforts to clean the environment, Giardia can persist in outdoor spaces and pet reinfection is possible.

How long does Giardia survive in the environment?

How often and for how long should I clean and disinfect my home after my dog or cat is diagnosed with Giardia infection?

How do I prevent my dog or cat from getting re-infected, or sickening my other pets, during treatment?

How do I treat my pet for Giardia infection?