Giardia in Cats

Cat Giardia Parasite

Giardia duodenalis is a protozoan parasite that can infect many different mammals, including cats, dogs, and people. There are a number of different strains of Giardia that are categorized by letters from A - H. Cats are typically infected with assemblage F, whereas people are generally susceptible to assemblages A and B. That said, while rare, it is possible for cats to harbor strains A and B, potentially causing infection in their owners.

The condition is most often seen in kittens and cats that are suffering from poor health due to other underlying conditions. 

Giardia can be challenging for pet parents to deal with since treatment isn't always effective and reinfection will often occur.

How is giardia spread?

All strains of giardia are transmitted via the fecal-oral route. This means that the giardia parasites are present in an infected cat's stool, when other animals (or people) come in contact with the infected stool the parasite makes its way into the new host's body by ingestion or inhalation. This can happen by direct contact with contaminated stool, by the inhalation of soil that has been in contact with contaminated stool, or by ingesting water that has become contaminated.

Can you get giardia from your cat?

Giardia infections are common in people however drinking contaminated water is the most common way for people to catch giardia. 

While it is possible for cats to harbor the A  strain of giardia (dogs can harbor the B strain) that people are susceptible to, the spread of giardiasis from cats to people is not very common.

Nonetheless, precautions, such as wearing gloves while changing cat litter, washing your hands well after handling your cat, and disinfecting items that come in contact with your cat is advised. (including the litter box, water bowls. bedding, toys etc.). People with compromised immune systems should be particularly diligent about disinfecting if their cat is diagnosed with giardia.

Disinfect surfaces that your cat comes in contact with using a solution of chlorine bleach at a dilution of 1:16 or 1:32.

What are the signs of giardia in cats?

Giardia parasites damage the cat's intestinal wall and typically lead to the sudden onset of foul smelling diarrhea. Not all cats infected with Giardia will show signs of infection, however if your cat has giardiasis you may also notice:

• Cat's stool is soft to watery and may have a greenish tinge or contain blood.
• Excess mucus in the feces may be apparent.
• Vomiting may occur in some cases.
• Lethargy in some cases.
• Symptoms of giardiasis listed above may persist for several weeks resulting in weight loss.

It is not uncommon for diarrhea related to giardiasis may be intermittent. Fevers are not typically associated with giardia infections in cats.

What is the treatment for cat giardia?

Giardia in cats can be challenging to completely eliminate and may require repeated treatments or combinations of treatments in order to completely eliminate the parasite. The elimination of the disease can be difficult because some giardia strains can be resistant to medication. As a result, multiple drugs or more than one attempt at therapy may be needed.

Fenbendazole and metronidazole are the most commonly prescribed treatments for giardia in cats.

• Fenbendazole may reduce clinical signs and shedding of the parasite. This treatment is administered to the infected cat orally for 3 to 5 days and is safe for pregnant cats.
• Metronidazole is a medication that appears to be more effective at treating giardia in cats than dogs. Treatment is given for 5 to 7 days and is not safe for pregnant cats.

In certain cases, the two medications can be given in combination to fight giardiasis.

Your vet may also prescribe a highly digestible diet until your cat's stool hardens. Prolonged bouts of vomiting and diarrhea can quickly result in dehydration so it's important to ensure that your cat remains well hydrated.

How long will my cat have giardia?

It generally takes between 3 to 5 days for the parasites to be cleared from the stool once antibiotic treatment begins, and 5 to 7 days for symptoms to resolve.

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.