Amphotericin B for Cockatiels: Uses, Nebulization & 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 antifungal medication used by avian veterinarians when a cockatiel has a serious or hard-to-treat fungal infection. It belongs to the polyene antifungal class and works by binding to ergosterol in fungal cell membranes, which damages the fungus and helps stop its growth.

In birds, your vet may use amphotericin B in several ways depending on where the infection is located. It can be given by nebulization for respiratory disease, intratracheally or topically in selected cases, and sometimes as part of treatment plans for certain yeast or fungal infections involving the respiratory tract or upper digestive tract. Because fungal disease in cockatiels can look vague at first, this medication is usually only started after your vet has examined your bird and decided it fits the likely diagnosis.

This is not a medication to start at home without guidance. Amphotericin B can be very helpful in the right case, but it also needs careful handling, exact dilution, and monitoring, especially if injectable forms are used. For many cockatiels, it is part of a broader plan that may also include supportive care, improved husbandry, nutrition support, and follow-up testing.

In cockatiels, amphotericin B is most often discussed for fungal respiratory disease, especially aspergillosis, where fungal plaques or infection affect the air sacs, lungs, trachea, or syrinx. Merck Veterinary Manual lists avian dosing for nebulized, intratracheal, and intravenous amphotericin B, which reflects its established use in bird medicine when your vet believes a fungal infection is present.

Your vet may also consider amphotericin B for some yeast infections, including Candida and, in selected birds, Macrorhabdus ornithogaster infection, often called avian gastric yeast. That said, response can vary. Published reports describe inconsistent efficacy and possible resistance in some Macrorhabdus cases, so your vet may recommend repeat fecal testing, crop evaluation, or a different antifungal plan if your cockatiel is not improving.

Because cockatiels can hide illness, the signs that lead to treatment may be subtle at first. A bird with fungal disease may show tail bobbing, open-mouth breathing, voice change, reduced activity, weight loss, regurgitation, poor appetite, or chronic fluffing. Those signs do not confirm a fungal infection on their own, so your vet may recommend imaging, bloodwork, endoscopy, cytology, or fungal testing before choosing amphotericin B.

Amphotericin B dosing in birds is highly route-specific, which means the dose depends on whether your vet is using it by nebulization, intratracheal administration, intravenous injection, or another route. Merck Veterinary Manual lists avian respiratory therapy guidance of 1 mg/mL solution in sterile water or saline for nebulization for 15 minutes every 6 to 12 hours, and another Merck table lists 0.25 to 1 mg/mL for nebulization for 10 to 20 minutes twice daily. Merck also lists 1 mg/kg nebulized over 15 minutes every 24 hours for 10 to 14 days in birds and 1 mg/kg intratracheally every 8 to 12 hours in avian patients.

Those numbers are reference doses for veterinarians, not home instructions. Your cockatiel's actual plan may differ based on the suspected fungus, severity of breathing changes, body weight, hydration status, and whether your vet is combining amphotericin B with another antifungal such as an azole. Nebulization plans also depend on the nebulizer type, chamber size, particle delivery, and how well your bird tolerates treatment.

If your vet prescribes nebulization, ask for a written mixing and administration plan. Small errors in dilution can matter. Do not substitute saline, sterile water, concentration, or treatment time unless your vet tells you to. If your cockatiel struggles to breathe during treatment, becomes panicked, or seems weaker afterward, stop and contact your vet right away.

For digestive yeast problems such as suspected avian gastric yeast, oral amphotericin B may be used by some avian vets, but protocols vary and follow-up testing is often needed. Because published evidence shows variable success in some birds, your vet may adjust the plan if droppings, weight, appetite, or repeat testing do not improve.

See your vet immediately if your cockatiel has worsening breathing, severe weakness, collapse, marked decrease in appetite, or rapid weight loss while on amphotericin B. Birds can decline quickly, and respiratory fungal disease itself can become an emergency.

Side effects depend on the route used. With nebulization, some birds show stress, agitation, temporary coughing, increased respiratory effort, or intolerance of the chamber. With systemic or injectable amphotericin B, vets are more concerned about kidney effects, dehydration, electrolyte changes, and reduced appetite. In mammals, amphotericin B is well known for nephrotoxicity, and veterinary references recommend monitoring during treatment. In birds, published reviews note that documented nephrotoxicity is less clear than in mammals, but careful monitoring is still appropriate, especially in a small patient like a cockatiel.

At home, watch for less eating, fewer droppings, vomiting or regurgitation, lethargy, sitting fluffed for long periods, increased thirst, or any change in balance or responsiveness. Because cockatiels are so small, even a short period of poor intake can become serious. Daily gram-scale weights are one of the most useful ways to catch trouble early.

If your cockatiel is receiving injectable amphotericin B or has other health problems, your vet may recommend repeat exams, bloodwork, and hydration checks. Monitoring is not a sign that something is wrong. It is part of using a strong antifungal as safely as possible.

Amphotericin B can interact with other medications that affect the kidneys, hydration status, or electrolyte balance. In veterinary medicine, concurrent use with other nephrotoxic drugs raises the most concern. Merck specifically notes amphotericin B as a nephrotoxic exposure that can increase risk when combined with aminoglycosides such as gentamicin or amikacin, and risk may also rise with some diuretics or other drugs that reduce kidney perfusion.

In cockatiels, your vet will also think about how amphotericin B fits with other antifungals and supportive medications. It may be used alongside azole antifungals in some fungal cases, but that does not mean every combination is right for every bird. The full plan depends on the suspected organism, where the infection is located, and how your cockatiel is tolerating treatment.

Tell your vet about every medication and supplement your bird receives, including probiotics, crop medications, pain relievers, antibiotics, and anything added to water or food. Also mention if your cockatiel has a history of kidney disease, dehydration, chronic weight loss, or poor appetite, because those details can change how aggressively your vet uses amphotericin B and how often monitoring is needed.