ASK THE VET (Antibiotic Considerations in the Treatment of Bacterial Disease)

This article first appeared in SQUAWK, the newsletter of the Big Apple Bird Association and is reprinted with permission.

Bacterial diseases often occur in companion and aviary birds. Birds often mask signs of illness and are usually presented to a veterinarian in a debilitated, advanced state of disease. In order for treatment to be successful, the correct diagnosis and appropriate medical management are necessary.

Antibiotics are used in the treatment of bacterial infections. Whenever possible, cultures should be taken from the site of infection to identify the organism present and the most effective antibiotic against that organism.

Treatment is often instituted before results of cultures are obtained since identification of the most appropriate antibiotic based on sensitivity may take three to four days. Antibiotics may be changed if a more effective antibiotic against the inciting organism is demonstrated. Several factors must be understood once the most appropriate antibiotic is chosen. Proper dose is essential. The bird must be weighed accurately and given the calculated amount of medicine. Underdosing may lead to treatment failure and drug resistance, while excessive amounts may be toxic and damage the kidneys or liver.

The route of administration of the drug is very important. A bird in an advanced state of illness must be given medication that will be absorbed rapidly and reach therapeutic levels in the bird's body. If a bird is too sick to eat or drink, putting medication in the food or water will not be effective. Birds may be given medication by intravenous injection, intramuscular injection, or by direct administration into the mouth. Medicated food may be used under certain circumstances, but the patient must be eating in order to obtain therapeutic levels in his body.

The frequency of administration and the duration of treatment must be closely adhered to. Certain drugs require twice a day or three times a day administration in order to obtain optimal levels in the patient. Dosing less than the recommended number of times can lead to treatment failure and antibiotic resistance. Treatment must be continued for the prescribed period of time. Stopping medication too soon can lead to the failure of eliminating the infection.

The goal of antibacterial therapy is to aid in the elimination of the infecting agent from the patient. Antibiotics play only a partial role, the host's immune system is required to clear the infection. Supportive care and good nutrition are essential for a successful outcome.