Controlling Parasites With Metronidazole for Dogs

A viable method of controlling certain gastro-intestinal parasites is Metronidazole for dogs. This is an advanced drug commonly used to treat more difficult infections that cannot be combated with a lesser antibiotic.

What is Metronidazole?

Metronidazole is an antibiotic that fights protozoan infections in dogs. It is the active ingredient in several brand name drugs including MetroCream, Protostat, Metrogel, Metizol and Flagyl. Most commonly, these infections are found in the GI tract, most internal organs, in deep wounds or tissues, and in the vagina. It is commonly prescribed to treat Giardia, Entamoeba, Trichomonas and Balantidium. Metronidazole can also be used to treat anaerobic bacterial infections.

Metronidazole is not FDA-approved for use in veterinary medicine, although this drug is commonly used in dogs.

Side Effects

Metronidazole has several noted side effects in dogs, and these are often noted seven to twelve days after the first dose. Common side effects may include:

  • Excessive salivation
  • Gagging
  • Regurgitation
  • Nausea
  • Vomiting
  • Decreased appetite

Less common side effects may also occur, such as:

  • Diarrhea
  • Depression
  • Lethargy
  • Weakness
  • Anemia
  • Liver failure
  • Bloody urine

These side effects are more serious, and if noted, should be mentioned to your veterinarian.

Metronidazole Toxicity and Overdose

Most dogs susceptible to overdose, known as acute toxicity, are those with preexisting liver problems, and those who receive medication for several weeks at a high dosage. As an overdose in Metronidazole affects the brain and equilibrium, symptoms of an overdose involve largely coordination problems such as:

  • Staggering
  • Disorientation
  • Involuntary eye movements
  • Poor appetite
  • Tremors
  • Seizures
  • Stiffness
  • Depression

These are all neurological reactions to an overdose and, if occurring, your dog should immediately stop receiving doses. Some animals must receive immediate medical attention that may require constant intravenous fluids.

There is no antidote for Metronidazole toxicity. Symptoms of an overdose do not often disappear until one to two weeks or more after stopping the medication. Neurological signs of an overdose may remain present even after other symptoms have vanished.

Other Considerations

In laboratory tests, Metronidazole has caused birth defects in animals. Additionally, it should not be used in pregnant or nursing animals, and in puppies under eight months of age. Due to its tendency to disrupt the liver process and cause liver failure, it should be avoided or used with extreme caution in animals with preexisting liver or kidney damage. Using Metronidazole in conjunction with Tagamet, Dilantin, Phenobarbital or Coumadin is not recommended as Metronidazole may interact with them.

Metronidazole is a drug used to treat a wide variety of difficult bacterial ailments and protozoan parasite infections, and one method to explore when considering medication for your dog.