Different uses of metronidazole for dogs include treating infections and parasites such as Giardia. Metronidazole is an antibiotic and is most effective in treating infections categorized as anaerobic infections. These infections thrive without oxygen and can occur in deep wounds and in the mouth. Metronidazole is also effective in the treatment of canine diarrhea, pancreatic disorders and tetanus. While receiving therapy with this medication, the dog should be monitored closely by his owners and veterinarian for side effects.
Also known as Flagyl®, metronidazole is also used in humans to treat certain bacterial infections. It is available only by prescription. Although metronidazole for dogs is considered to be safe, it can produce side effects and should never be given to dogs who are pregnant.
Common side effects of Flagyl® for dogs include gastrointestinal upset, loss of appetite, and hypersalivation. In addition, persistent gagging, retching and pawing at the mouth may also occur. These side effects, however, are usually mild and temporary. Other, more serious side effects include profound weakness, diarrhea, and liver dysfunction.
Other important side effects of metronidazole for dogs include bloody urine, disorientation, and tremors. In rare instances, seizures can occur, as can severe muscle stiffness. Fortunately, these side effects are not typical when metronidazole is given on a short-term basis, and are only rarely seen when treatment is prescribed in high doses over long periods of time.
Certain conditions may make it necessary for the veterinarian to prescribe metronidazole for dogs over long periods of time. An example of such a condition is a stubborn infection known as small intestinal bacterial overgrowth (SIBO). During treatment for SIBO, toxicity may occur, and if it does, the medication needs to be discontinued immediately.
If the dog experiences toxicity from the antibiotic, hospitalization may be required. Since severe vomiting can be a symptoms of toxicity, intravenous fluids may be necessary to prevent dehydration. In addition, medications to relieve vomiting and anti-anxiety medications may be prescribed. Sometimes, when the offending medication is discontinued and the dog is re-hydrated, he recovers quickly and without long-term complications.
To determine if organ damage has occurred, blood tests might be recommended to check for abnormalities in kidney and liver function. In addition, it may take weeks for the dog to recuperate, and occasionally the prognosis of metronidazole toxicity is poor. When a dog is receiving metronidazole therapy for an infection and exhibits loss of appetite, disorientation, and difficulty walking, the owner needs to seek emergency veterinary care to reduce the risk of multiple organ failure and severe toxicity.