Proventricular Dilatation Disease (PDD) in Birds: A Vet’s 2025 Guide 🐦🩺

By Dr Duncan Houston BVSc – avian veterinarian & founder of Ask A Vet 🩺🐾

Proventricular Dilatation Disease (PDD) is a progressive, often fatal, neurologic and gastrointestinal condition that affects parrots and other birds. Once known as "Macaw wasting disease," it's linked to Avian Bornavirus (ABV). While incurable, PDD can be managed in affected birds and controlled within flocks. This 2025 vet guide covers:

• 🧠 What PDD is and which birds are at risk
• 🚩 Clinical signs—digestive and neurologic
• 🔍 Diagnostic testing: imaging, PCR, biopsy, necropsy
• 🛌 Supportive care: NSAIDs, prokinetics, nutrition
• 🚫 Flock management and biosecurity
• 📱 How Ask A Vet can support care and decision-making

1. 🦠 What is PDD?

PDD is a neurologic disease affecting the nerves of the GI tract (crop, proventriculus, ventriculus) and sometimes the CNS—brain and spinal cord—causing motility dysfunction and neurologic signs. It's strongly associated with Avian Bornavirus infection :contentReference[oaicite:1]{index=1}.

2. 🐣 Birds At Risk

PDD occurs mainly in psittacine species like macaws, African greys, Amazons, cockatoos, conures, and cockatiels. Over 50 species, including some non-parrots, can be affected :contentReference[oaicite:2]{index=2}.

3. 🚩 Signs & Symptoms

3.1 Gastrointestinal Signs

• Chronic weight loss, muscle wasting (“wasting disease”)
• Regurgitation and vomiting mucus
• Undigested food (whole seeds) in droppings
• Crop or proventricular enlargement seen on radiographs :contentReference[oaicite:3]{index=3}

3.2 Neurologic Signs

• Tremors, ataxia, weakness, paralysis
• Seizures or unusual head movements :contentReference[oaicite:4]{index=4}
• Sudden death—even without prior signs—possibly from cardiac or CNS effects :contentReference[oaicite:5]{index=5}

4. 🔬 Diagnosis

4.1 Imaging (Radiographs/Fluoroscopy)

Contrast studies with barium reveal dilated proventriculus and delayed transit time :contentReference[oaicite:6]{index=6}.

4.2 PCR / Serology

RT-PCR on cloacal/choanal swabs or blood + serology (ELISA/Western blot) can detect ABV. Multiple tests (3 months apart) needed due to intermittent shedding and false results :contentReference[oaicite:7]{index=7}.

4.3 Biopsy / Necropsy

Crop or proventriculus biopsy shows lymphoplasmacytic ganglioneuritis in nerves. Definitive diagnosis relies on necropsy, examining neural tissue throughout organs :contentReference[oaicite:8]{index=8}.

5. 🧪 Treatment & Supportive Care

There is no cure or effective antiviral for PDD. Treatment focuses on support and addressing complications :contentReference[oaicite:9]{index=9}.

• NSAIDs: Meloxicam (0.5–1 mg/kg BID), celecoxib or robenacoxib may reduce inflammation—mixed results, some studies reported worsened lesions :contentReference[oaicite:10]{index=10}.
• Prokinetics: Cisapride or metoclopramide before feeding to aid GI motility :contentReference[oaicite:11]{index=11}.
• Omega oils: Flax or omega 3/6 reduce inflammation (0.1–0.44 mL/kg) :contentReference[oaicite:12]{index=12}.
• Gabapentin: For seizures or neuropathic pain (10–25 mg/kg Q12 h; up to 50 mg/kg for self-mutilation) :contentReference[oaicite:13]{index=13}.
• Symptom control: Fluid balance, assisted feeding, antibiotics/antifungals for secondary issues :contentReference[oaicite:14]{index=14}.

6. 🔄 Long-Term Outlook

PDD is progressive and incurable; relapses are probable. Some birds live month to years with care, but prognosis remains guarded :contentReference[oaicite:15]{index=15}.

7. 🧼 Flock Management & Prevention

• Isolation: Separate ABV-positive or suspected birds from healthy ones :contentReference[oaicite:16]{index=16}.
• Testing: PCR + serology repeated over months—healthy birds may carry without symptoms :contentReference[oaicite:17]{index=17}.
• Hygiene: Daily cleaning, disinfect droppings; ABV is environmentally labile and inactivated by heat/dryness/disinfectants :contentReference[oaicite:18]{index=18}.
• Biosecurity: Quarantine new birds for 90+ days, test before integration :contentReference[oaicite:19]{index=19}.
• Breeding control: Avoid breeding positive birds; vertical transmission possible. In outbreaks, suspend breeding and disinfect housing :contentReference[oaicite:20]{index=20}.

8. 📱 Using Ask A Vet

• Review images/videos of weight loss, regurgitation, posture.
• Interpret diagnostic results and design testing schedules.
• Tailor supportive care: dosing NSAIDs, prokinetics, gabapentin.
• Guide housing decisions, quarantine, and outbreak management.

9. 🧠 Quick Reference Table

🧡 Final Takeaways

• PDD is a progressive, incurable neurologic condition with GI and neurologic signs.
• Diagnosis requires imaging and diagnostic testing; definitive only via biopsy/necropsy.
• Treatment is supportive: NSAIDs, prokinetics, gabapentin, assisted feeding.
• Strict flock management—testing, isolation, and hygiene—helps prevent spread.
• Ask A Vet app supports diagnosis, management, and flock health decisions.

PDD remains one of the most challenging avian diseases in 2025—but with vigilance, supportive care, and strong flock biosecurity, you can help your birds live as well as possible. For expert support, reach out via the Ask A Vet app or visit AskAVet.com. Wishing your flock health and strength. 🐾