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What is Giardia in cats?

Giardia is a group of protozoan parasites (identified by the letters A through H) that can infect people, as well as dogs and cats, and lead to symptoms such as diarrhea and upset stomach. Today our San Gabriel vets share tips on how to tell if your cat may be infected with Giardia, and what you can do to help resolve symptoms and prevent family members and other pets from becoming infected.

Cat Giardia Parasite

Giardia duodenalis is a protozoan parasite that infects a wide range of mammals, including cats, dogs, and humans. There are several strains of Giardia that are labeled with letters ranging from A to H. Cats are usually infected with assemblage F, whereas humans are usually infected with assemblages A and B. However, while it is uncommon, cats can harbor strains A and B, potentially infecting 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?

The fecal-oral route is used by all giardia strains. This means that giardia parasites are present in the stool of an infected cat, and when other animals (or people) come into contact with the infected stool, the parasite enters the new host's body via ingestion or inhalation. This can occur through direct contact with contaminated stool, inhalation of soil contaminated with contaminated stool, or ingestion of contaminated water.

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. 

However, precautions such as wearing gloves when changing cat litter, thoroughly washing your hands after handling your cat, and disinfecting items that come into contact with your cat are recommended. (This includes the litter box, water bowls, bedding, toys, and so on). If their cat has giardia, people with compromised immune systems should be especially diligent about disinfecting.

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

Can a dog infect a cat with giardia?

Because dogs harbor the B strain while cats harbor the A strain, dog strains of Giardia are not known to infect cats, and cat strains are not known to infect dogs. It is, however, still a good idea to keep your pets separated if one of them tests positive for Giardia or is recovering from a recent infection.

What are the signs of giardia in cats?

Giardia parasites cause intestinal damage in cats, resulting in sudden bouts of foul-smelling diarrhea. Not all Giardia-infected cats will exhibit symptoms of an 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 veterinarian may also recommend a high-digestibility diet until your cat's stool hardens. Prolonged bouts of vomiting and diarrhea can quickly lead to dehydration, so keep your cat hydrated at all times.

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.

Is your cat experiencing the symptoms of giardia? Contact us today to book an appointment for your feline friend. Our vets are experienced in treating many parasitic conditions in pets.

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