Aspergillosis is the most lethal fungal infection of pet macaws and other large parrots, often presenting as silent chronic disease — voice change, exercise intolerance, weight loss — before owners notice the bird is in trouble. African greys, macaws, and Amazons are especially susceptible. Diagnosis hinges on serology and tracheoscopy; treatment with voriconazole or itraconazole over months can be curative if caught before severe lung pathology develops (AAV Basic Care for Companion Birds, 2019). Voice change in a macaw is a red flag, not a cute quirk.
Last reviewed: June 2026
What Aspergillosis Is
Aspergillosis is infection of the respiratory tract with Aspergillus fungus (most often A. fumigatus). Spores are inhaled from contaminated food, bedding, or environment. Healthy immunocompetent birds clear the spores; immunosuppressed, malnourished, or stressed birds develop infection. The fungus colonizes the syrinx (voice box), trachea, lung tissue, and air sacs. Large parrots — macaws, African greys, Amazons — are particularly susceptible because of their long lifespan and frequent vitamin A or general nutritional deficiencies in pet diets. As described in the Carpenter Exotic Animal Formulary, aspergillosis is a leading cause of death in pet psittacines.
Signs Owners First Notice
The hallmark early sign is voice change — a previously talkative or whistling macaw becomes hoarse, raspy, or silent. Owners also describe increased respiratory rate at rest, tail bobbing with breaths, decreased exercise tolerance, weight loss, lethargy, and occasional open-mouth breathing. Some birds show only nonspecific decline. Advanced disease produces severe respiratory distress, granulomas visible in the airway, and abdominal swelling from air sac involvement.
Why It's So Hard to Catch Early
Birds hide illness from instinct, and aspergillosis often progresses for weeks before clinical signs appear. By the time owners notice voice change, the lung and air sac disease can be substantial. Annual avian wellness exams with bloodwork and weight tracking are the best screening tool for high-risk species. As reviewed in Mitchell and Tully's Manual of Exotic Pet Practice, baseline weight loss of more than 10 percent in a high-risk parrot warrants aspergillosis screening even without respiratory signs.
How It's Diagnosed
Aspergillus antibody and antigen serology (galactomannan, PCR) screens for active disease, with consistent diagnostic patterns described in the JEPM clinical review series (Beernaert et al., 2010, JEPM). Plain radiographs may show air sac thickening or pulmonary lesions in advanced cases. Endoscopy with tracheoscopy and laryngoscopy directly visualizes plaques and granulomas in the syrinx — often the highest-yield diagnostic. Cytology and culture of airway exudate confirm the diagnosis. CBC typically shows leukocytosis with monocytosis. The 2019 AAV companion bird care document recommends combined antibody/antigen testing and imaging.
Treatment
Long-course antifungal therapy is the foundation: oral voriconazole (10 to 18 mg/kg twice daily) or itraconazole over 3 to 6 months. Voriconazole reaches better tissue levels and has become the drug of choice for serious cases, but it requires therapeutic monitoring and is expensive. Nebulization with antifungal agents (terbinafine, amphotericin) is added for upper airway disease. Surgical or endoscopic debridement of plaques in the syrinx may be necessary. Supportive care includes correcting nutritional deficiencies, particularly vitamin A.
When to See a Vet
Call your vet today if:
- Voice change in a previously vocal macaw or other parrot
- Tail bobbing with breaths or increased respiratory effort at rest
- Decreased exercise tolerance, reluctance to fly or climb
- Unexplained weight loss in a high-risk parrot
- A bird that suddenly stops eating its favorite foods
Go to the ER immediately if:
- Open-mouth breathing at rest
- Cyanotic (blue) gape or tongue
- Severe lethargy with fluffed posture and weakness
- Sudden collapse or inability to perch
- Audible wheezing or clicking with breathing
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Frequently Asked Questions
Are some species really more susceptible?
Yes — African greys, macaws, Amazons, gyrfalcons, and many seabirds are notably susceptible. Cockatiels, budgies, and conures are at lower but still meaningful risk. Risk is greatest in birds on seed-only diets, in damp poorly ventilated environments, or under chronic stress.
How much does diagnosis and treatment cost?
Initial avian exam at a board-certified avian vet typically runs $150 to $400 in the US. Aspergillus serology costs $150 to $400. Radiographs add $200 to $500. Endoscopy under anesthesia is $800 to $2,500. Voriconazole compounded for a macaw runs $200 to $600 per month for 3 to 6 months. Itraconazole is less expensive at $80 to $300 per month. Total treatment costs for a confirmed case often reach $3,000 to $8,000 over the treatment course. Early diagnosis before extensive lung damage dramatically improves outcomes.
Can my bird be cured?
Yes — early-stage disease in an otherwise healthy bird has a good cure rate with 3 to 6 months of appropriate antifungal therapy. Advanced disease with extensive air sac involvement has a guarded prognosis even with aggressive treatment. Outcome depends most on how early the disease is caught.
Is aspergillosis contagious?
Bird-to-bird transmission is rare in practice — aspergillosis is mostly an environmental infection. However, shared moldy food, damp bedding, or poor ventilation creates risk for all birds in the household. Improving husbandry protects unaffected cagemates.
Still Not Sure if Your Bird Needs a Vet?
When you're not sure if this is wait-and-see or call-tonight, Voyage AI Vet triages in under 2 minutes. Describe what you're seeing in chat, share a short audio recording of any voice change and a video of your bird at rest, or hop on a live video call if you want a second pair of eyes. Every answer comes with citations to the actual veterinary literature it's pulling from — so you see exactly where the guidance comes from, not just a chatbot's word.