Treating Giardia Infections in Cats

Many cats have sensitive digestive tracts.  This becomes a huge problem when they need to be given a course of antibiotics.  Allion C. writes:

Ms. T has a terrible case of giardia. She can’t eat anything. She is so dehydrated that I hardly recognize her. What can she eat?

Allion, the first step is to take Ms. T to the vet in order to confirm the diagnosis and get her on antibiotics immediately.  We assume you've done this step and the combination of the infection and the antibiotics is making it impossible for Ms. T to keep anything on her stomach.  This isn't uncommon, but it can be life-threatening if it continues.

For those of you who don't know, giardia intestinalis is an intestinal parasite that causes damage to the digestive tract.  If left untreated, it can actually cause death in older animals and those with compromised immune systems.  It's important that a giardia infection be accurately diagnosed and treated as quickly as possible after symptoms appear.  A stool sample may be required for diagnosis. 

Treatment usually consists of a five to seven day course of antibiotics.  The antibiotic usually prescribed is metronidazole.  Unfortunately, the antibiotic itself can wreak havoc with your cat's digestive tract since it not only kills the giardia, it also kills the good flora in her intestines that help her digestion.

Allion, you need to talk to your vet about adding additional medications to help Ms. T get through this treatment.  Some will add fenbendazole to help, or they may prescribe intravenous fluid therapy to keep Ms. T. hydrated.  Your veterinarian will have to make the call based on Ms. T's symptoms.  Be sure to bring a fecal sample from the litter box on your visit so that the vet can test to see if the giardia have been eliminated.

In order to get her to eat now, there are several things you can try.  Bear in mind that every cat is different and there will be a lot more misses than hits.  Don't allow yourself to get discouraged.  First, Ms. T should be on a wet food only diet.  If she isn't, now is the time to transition her.  A raw food diet will be the best thing for her if you can afford it.  You want to tempt her with a food that she likes a lot and has a high moisture content.  Some people suggest turkey or chicken baby foods but we feel this is problematic because they often contain ingredients like onion powder that are harmful to cats.

Once it's confirmed that the infection has been removed, you can work to rebuild the good flora in Ms. T's system.  Your vet may have specific recommendations for this depending on her state.  We usually recommend a probiotic like FortiFlora.  Sometimes FortiFlora even helps a nauseated cat like Ms. T to eat more because the flavor is so attractive!


If you and your vet choose to administer a probiotic, don't forget to feed the new bacteria.  You're not only feeding Ms. T; you're also keeping those healthy bacteria alive in her intestinal tract; something most pet food manufacturers neglect.  We've had great success by adding a teaspoon of pumpkin puree to a cat's wet food twice a day.  You'll want to make sure it's 100% pure pumpkin, with no fillers.  If it's labeled "organic", even better.  New studies suggest that cats really don't need additional fiber in their diets and that it might actually contribute to hairball problems.  Unfortunately, we just don't know for sure so we recommend feeding pumpkin only when needed to aid the good bacteria in the probiotics.


Once you have Ms. T back to her usual self, you may want to consider where she picked up the giardia infection in the first place.  It's usually inhaled off the ground or through another animal's feces.  Keeping Ms. T indoors will certainly help to protect her from such infections.

Good luck with Ms. T's treatment, Allion.  We wish you all the best!