Managing Feline Colitis with Metronidazole

Feline colitis may be caused by various factors such as a bacterial infection, stress, allergy, parasitic invasion or colon cancer. When the lining of the colon gets inflamed, the resulting condition is called colitis. The organ affected by colitis is the large intestine, whose function is to absorb water from indigestible food and pass the waste from the body.

Symptoms of Colitis

  • Discomfort while passing feces
  • Frequent need to defecate
  • Intermittent diarrhea
  • Stools with mucous
  • Loss of appetite
  • Constipation
  • Pain and discomfort in the abdomen
  • Dehydration
  • Vomiting


Your vet will perform a physical examination of your cat, with a look at her history and symptoms. Colitis can occur suddenly, or it can be chronic or episodic. This will be taken into account to get an idea of the treatment. Various tests will be conducted to rule out other diseases and to confirm colitis.

  • Stool test for the presence of bacteria, parasites and protozoa
  • Complete blood count
  • Urine test
  • Tests to check for cancer
  • Tests to check for pancreatitis
  • Tests for hyperthyroidism


The removal of the cause of inflammation is usually the way to treat colitis. Some common elements in the treatment of colitis are listed below.

  • Introduction of a low fat, high fibre diet
  • De-worming
  • Rehydration therapy
  • Anti-inflammatory medicines and antibiotics
  • Metronidazole for Colitis

Metronidazole is an antibiotic which penetrates the DNA of the bacteria causing infection. It then proceeds to damage the DNA in such a way that the bacteria and protozoa are unable to multiply. This finally kills the microbes and finishes the infection. This drug is particularly meant for bacteria which don't need oxygen to grow. These anaerobic bacteria are usually found in the intestines, bones and gums. This is the reason, that metronidazole is so effective in the case of colitis, which affects the large intestine.

It is recommended that you complete the course prescribed, even if your cat seems to be feeling better. Metronidazole has some side effects you should be aware of. Generally this drug is safe for cats, but as with all medications, it can affect some felines adversely.

Side Effects of Metronidazole

  • Diarrhea
  • Drooling
  • Dry mouth (licking or pawing at the mouth)
  • Drop in white blood cell count (neutropenia)
  • Liver failure ( hepatoxicity)
  • Bloody urine (hematuria)
  • Neurological disorders
  • Listlessness
  • Lack of appetite (anorexia)
  • Nausea
  • Vomiting

The prolonged use of metronidazole can prove to be toxic for your cat. Be alert to the reactions your cat may display as a result of this.

  • Back and forth eye movement
  • Seizures
  • Rigidity
  • Disorientation/staggering
  • Holding the head at a tilt
  • Tremors
  • Drop in heart beat

If your cat shows any of these symptoms, discontinue the use of the drug immediately. Usually she should recover within 2 weeks, but there have been cases where the reaction has been acute and fatal. Metronidazole should not be administered to a pregnant cat or one with hypersensitivity to the drug. The drug should not be taken on an empty stomach.