Amphotericin B for Turkey: Uses, Dosing & Side Effects

This information is for educational purposes only. Never give your pet any medication without your veterinarian's guidance. Dosing, frequency, and safety depend on your pet's specific health profile.

Amphotericin B is a prescription polyene antifungal medication used to treat serious fungal infections. It works by binding to ergosterol in the fungal cell membrane, which damages the fungus and can help stop the infection from spreading. In avian medicine, your vet may consider it when a turkey has a confirmed or strongly suspected fungal disease, especially one affecting the respiratory tract or upper digestive tract.

In turkeys, amphotericin B is an extra-label medication, meaning it is not specifically FDA-approved for this species and must be used under veterinary supervision. That matters because turkeys are food-producing birds, so your vet also has to think about legal use, residue concerns, and any needed withdrawal guidance before treatment starts.

This is not a medication to start at home. Amphotericin B can be given by different routes in birds, including oral suspension, nebulization, intratracheal treatment, or intravenous administration, depending on the infection site and how sick the bird is. The route, concentration, and monitoring plan all affect safety.

In turkeys, amphotericin B is used most often when your vet is concerned about fungal disease, especially aspergillosis. Aspergillosis is a well-known respiratory fungal disease in poultry, including young turkeys, and can affect the lungs, air sacs, eyes, or sometimes other tissues. In birds more broadly, amphotericin B is also used for some yeast infections, including infections involving the upper digestive tract.

Your vet may choose amphotericin B as part of a larger treatment plan rather than as the only therapy. For example, birds with respiratory aspergillosis may need environmental cleanup, oxygen support, fluids, nutritional support, endoscopic evaluation, or combination antifungal therapy. In flock situations, treatment decisions can be very different from those for an individual pet turkey because prognosis, handling stress, and food-animal regulations all matter.

Because fungal disease can look like bacterial pneumonia or other respiratory illness, your vet may recommend testing before treatment when possible. That can include imaging, endoscopy, cytology, culture, or other diagnostics to help confirm whether amphotericin B is a reasonable option.

Amphotericin B dosing in birds depends heavily on the formulation, route, and disease being treated. Published avian references list several protocols, including 1.5 mg/kg IV every 8 hours for 3-5 days, 1 mg/kg by nebulization over about 15 minutes every 24 hours for 10-14 days, and 1 mg/kg intratracheally every 8-12 hours for selected respiratory cases. Merck also lists an oral suspension dose of 100 mg/kg by mouth twice daily for 30 days in pet birds for certain fungal gastrointestinal infections.

Those numbers should not be used as a home dosing chart for a turkey. Turkeys vary by age, body weight, hydration status, production status, and disease severity. Your vet may adjust the plan based on kidney values, uric acid, hydration, response to treatment, and whether the goal is individual treatment or flock-level decision-making.

If your vet prescribes amphotericin B, ask exactly which formulation is being used. Injectable amphotericin B, compounded oral suspensions, and respiratory preparations are not interchangeable. A small change in concentration can create a major dosing error in birds.

Because this drug can be hard on the kidneys in some species and because sick birds can decline quickly, follow-up matters. Your vet may recommend rechecks, weight tracking, hydration support, and bloodwork when feasible, especially if treatment is prolonged or systemic.

The side effect your vet watches most closely with amphotericin B is kidney injury. In mammals, nephrotoxicity is the major concern. Some avian references suggest birds may experience less renal toxicity than mammals, but that does not make the drug risk-free. A turkey that is dehydrated, critically ill, or receiving other kidney-stressing medications may be at higher risk.

Other possible problems include reduced appetite, lethargy, weakness, weight loss, vomiting or regurgitation in species that can do so, diarrhea, worsening dehydration, and irritation related to the route of administration. With nebulized or intratracheal treatment, some birds may show temporary stress, increased respiratory effort during handling, or airway irritation.

See your vet immediately if your turkey becomes markedly weak, stops eating, seems more dehydrated, has worsening breathing, or declines after starting treatment. In birds, subtle changes can become emergencies quickly.

If your vet is using systemic amphotericin B, monitoring may include hydration checks and lab work when practical. Early recognition of side effects can allow your vet to pause treatment, change the route, or switch to another antifungal plan.

Amphotericin B is most concerning when combined with other medications that can stress the kidneys. That can include certain antibiotics, some anti-inflammatory drugs, and other potentially nephrotoxic agents. If your turkey is already sick enough to need fluids, pain control, or multiple antimicrobials, your vet will weigh those combinations carefully.

It may also interact indirectly with drugs or conditions that affect hydration, electrolyte balance, or kidney perfusion. A dehydrated bird or one with pre-existing renal compromise may tolerate amphotericin B less well. That is one reason your vet may recommend fluids or supportive care alongside treatment.

Combination antifungal therapy is sometimes used in avian medicine, especially for difficult respiratory fungal disease. That does not automatically mean the drugs are unsafe together, but it does mean the treatment plan should be intentional and monitored. Always tell your vet about every medication, supplement, water additive, or compounded product your turkey is receiving.

For food-producing birds, there is an added layer: extra-label drug use and withdrawal planning. Your vet should be the one to decide whether amphotericin B is appropriate and what food-safety precautions apply in your specific case.