What is cat Giardia?
Giardia duodenalis is a protozoan parasite that can infect many different mammals, including humans, cats, and dogs. There are various different strains of Giardia that are categorized by the letters A through H.
Cats generally become infected with assemblage F, whereas humans are typically susceptible to assemblages A and B. While rare, it is possible for cats to harbor strains A and B, which means you can get Giardia from your cat.
This condition is most often seen in kittens and cats that are suffering from poor health as the result of other underlying conditions.
Giardia can be hard for pet owners to deal with because treatment isn't always effective and reinfection often occurs.
How Giardia Spreads
All strains of Giardia are transmitted via the fecal-oral route. The Giardia parasites are present in an infected cat's stool, and when other animals (or people) come in contact with the infected stool either through ingestion or inhalation, the parasite makes its way into the new host's body.
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.
Because of the way giardia is transmitted, it is possible for a dog to infect a cat with the parasite, if the cat comes in contact with infected dog feces.
Can humans get Giardia from cats?
Giardia infections are common in humans, however, people most often become infected by drinking contaminated water.
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, we recommend taking 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 (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.
Signs & Symptoms of Giardia In Cats
Giardia parasites can damage a cat's intestinal wall and typically lead to a 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:
- Excess mucus in the feces may be apparent.
- Cat's stool is soft to watery and may have a greenish tinge or contain blood.
- Lethargy in some cases.
- Vomiting may occur in some cases.
The symptoms of giardiasis listed above may persist for several weeks in cats which could cause weight loss. It's also not uncommon for diarrhea related to giardiasis to be intermittent.
In addition to this, we should also note that fevers are not typically associated with Giardia infections in cats.
Treating Giardia in Cats
It can be challenging to completely treat Giardia in cats. In order to completely get rid of the parasite, repeated treatments or a combination of different treatment methods might be required. Eliminating 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 treatments most often prescribed for giardia in cats.
- Fenbendazole may reduce clinical signs and shedding of the parasite. This treatment is administered to the infected cat orally for three to five 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 five to seven 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 three to five days for the parasites to be cleared from the stool once antibiotic treatment begins, and five to seven days for symptoms to resolve.
How do I prevent my cat from getting re-infected, or getting my other pets sick, during treatment?
Giardia cysts are infective immediately when passed into the environment, making reinfection highly possible.
Your cat's feces should be removed from the litter box quickly and disposed of and they should not share a litter box with any other cats in your household.
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.