Is Flagyl Effective for Cats?

That nasty giardia is out of my system, thanks to Flagyl.
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If Kitty suffers from internal parasite infections, Flagyl (metronidazole) effectively rids him of certain pests. Flagyl also treats other feline ailments, often in conjunction with other medications. While it's used generally internally, the topical form can help heal kitties with feline acne.


While metronidazole is an antibiotic, it's not prescribed for feline respiratory diseases. It's useful for different kinds of infections, such as anaerobic infections, where the germ grows without any oxygen. It also knocks out protozoa. The medication tastes bitter, so giving it in pill form to Kitty isn't easy. Your vet might recommend a compounding pharmacy to make up the drug in a more palatable feline format, including a liquid formula.


Giardia infects the intestines of many domestic animals, and cats are no exception. Cats suffering from giardia infection might lose weight and experience diarrhea. One tip that Kitty's loose bowels are due to giardia is an exceptionally bad smell and mucousy contents. According to the Merck Veterinary Manual, dosing felines with giardia with metronidazole for five days should get rid of the infection. Your vet determines the dosage based on Kitty's weight.

Other Uses

Because Flagyl interacts well with many other drugs, your vet might prescribe it along with steroids if Kitty has issues with inflammatory bowel disease or gingivitis. The latter condition affects the gums, making eating painful. Flagyl has the ability to penetrate bones to fight any infection there. Most antibiotics can't penetrate the body's blood/brain barrier, but Flagyl can. Your vet might prescribe the medication if Kitty is diagnosed with a disease of the central nervous system. Depending on the condition, Flagyl might be prescribed for short or long-term use.

Side Effects

While Flagyl generally is safe for felines, like any medication it might cause side effects in some cats. Kitty might stop eating, throw up or suffer from diarrhea. He might become lethargic, drool or experience dry mouth. If it's the latter, he'll paw at his mouth or frequently lick his lips. Long-term use of the drug or high dosages can cause toxicity. Those side effects are obvious and scary, including seizures, shaking, head tilting and other neurological issues. Most cats eventually recover when taken off the drug, but it might take up to two weeks, Rarely, cats succumb to the problems cause by side effects. Always give Kitty food along with Flagyl. Don't give it to pregnant or lactating cats.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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