The Side Effects of Metronidazole for Cats

If you face bacterial infections or parasitic invasions in your cats, Metronidazole could be a useful drug. It's an antibiotic and anti-protozoal, prescription drug which can be obtained from a vet. This is an extra label drug, which means that it's not approved for use in animals by the Food and Drug administration. Metronidazole is a generic name for Flagyl.

This drug interferes with the DNA of the bacteria and thus destroys it. Anaerobic bacteria are its target, and when used with other antibiotics, multiple infections can be warded off.

How Metronidazole Works

Unlike many antibiotics, metronidazole breaches the blood-brain barrier and gains access to central nervous system infections. It can also enter bone matter, making it effective in combating infections where other antibiotics may fail. In addition, it displays anti-inflammatory properties which can treat infections in the intestines, and is an effective anti-diarrhea medication. It regulates the immune system and helps relieve inflammatory disease of the bowels. It is useful in gum infections, skin infections and protozoal infections such as giardiasis, trichomoniasis and amebiasis.

Metronidazole is available in tablet, cream and liquid suspension form. It has a bitter taste and you may need to use pill pockets to get your cat to ingest it.

Generally this drug is safe for cats and has proved effective. As with any powerful drug, some cats may show side effects.

Side Effects of Metronidazole

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

Toxicity in metronidazole is rare and only occurs with very high doses or prolonged use. The effects of toxicity are usually seen in impaired functioning of the brain and difficulty in maintaining the body's balance.

Look Out for:

  • Disorientation or staggering
  • Holding the head at a tilt
  • Tremors
  • Involuntary eye movements
  • Seizures
  • Rigidity
  • Drop in heart beat (Bradycardia)

There is no particular home treatment for toxicity caused by metronidazole. The drug will have to be discontinued if any symptoms appear. Depending on the severity, recovery may take up to a fortnight. There is a slim chance of fatality as well, as the result of an acute reaction. Do not give metronidazole to a pregnant cat or one who has shown hypersensitivity to the drug earlier. It is recommended that you give the drug along with some food, and not on an empty stomach.