Proventricular Dilatation Disease in Conures: PDD and Avian Bornavirus

Proventricular dilatation disease, or PDD, is a serious condition seen in parrots, including conures. It is strongly linked to avian bornavirus infection, especially parrot bornavirus. In affected birds, inflammation damages nerves that help control the digestive tract. That can slow or stop normal movement of food, leading to stretching of the proventriculus, the glandular stomach.

PDD does not only affect the gut. Some conures develop neurologic signs because the same inflammatory process can involve nerves in other parts of the body. That is why one bird may mainly show weight loss and regurgitation, while another may also have weakness, tremors, poor coordination, or behavior changes.

This disease can be frustrating for pet parents because signs may come on gradually and can look like other bird illnesses at first. A conure may seem hungry but keep losing weight, or may pass poorly digested food in droppings. Some birds test positive for bornavirus and stay clinically normal, while others become very sick. That is one reason your vet usually looks at the whole picture rather than relying on one test alone.

PDD can be life-threatening, but the course is variable. Some conures decline quickly. Others can live for months or longer with careful supportive care, close monitoring, and a treatment plan tailored to their symptoms.

PDD is strongly associated with avian bornavirus, especially parrot bornavirus. Research and clinical experience support that this virus plays a major role, but the disease is still complex. Not every bird that tests positive for bornavirus develops obvious illness, and not every sick bird is easy to confirm with a single test. That suggests the immune response, viral strain, stress, and individual bird factors may all influence whether disease appears.

The main problem in PDD is inflammation of nerves, especially those serving the crop, proventriculus, ventriculus, and intestines. When those nerves do not work well, food may move too slowly, the proventriculus can enlarge, and the bird may lose weight even if it keeps eating. In some birds, inflammation also affects the brain or peripheral nerves, causing balance problems, tremors, or weakness.

Spread is thought to occur through exposure to infected droppings, feather dust, secretions, or contaminated surfaces, although shedding can be intermittent. That makes control challenging in homes with multiple birds. A healthy-looking bird may test positive, while a sick bird may test negative on one sample and positive later.

This is not a disease pet parents can diagnose at home. Many other problems can mimic PDD in conures, including heavy metal toxicity, bacterial or fungal gastrointestinal disease, parasites, liver disease, and other causes of regurgitation or weight loss. Your vet will help sort through those possibilities.

Diagnosis usually starts with a careful history and physical exam. Your vet will want to know about weight changes, appetite, droppings, regurgitation, activity level, and any neurologic signs. In birds, a gram-scale weight trend is often one of the most useful early clues.

Testing often includes radiographs, and sometimes contrast imaging or fluoroscopy, to look for an enlarged proventriculus and delayed movement of food through the gastrointestinal tract. Bloodwork may be done to look for dehydration, inflammation, muscle damage, anemia, low protein, or other illnesses that can look similar.

Because avian bornavirus shedding can be intermittent, your vet may recommend PCR testing of feces or cloacal swabs more than once. A single negative PCR does not rule out infection. Some clinicians also use serology, but results still need to be interpreted alongside symptoms and imaging findings.

In some cases, your vet may discuss crop biopsy, referral to an avian specialist, or necropsy if a bird dies. Necropsy with tissue evaluation remains one of the most definitive ways to confirm PDD. For living birds, diagnosis is often presumptive but clinically useful, based on the combination of signs, imaging, and repeat testing.

There is no vaccine currently available for avian bornavirus, so prevention focuses on reducing exposure and catching problems early. If you bring home a new conure or any new bird, quarantine first and schedule a wellness visit with your vet. In multi-bird homes, isolation of sick birds and careful hygiene matter because infected birds may shed virus intermittently.

Clean cages, bowls, perches, and surrounding surfaces regularly. Good sanitation, reducing crowding, lowering stress, and supporting strong overall health are practical steps that may help limit spread. Because the virus does not appear to be especially long-lived in the environment, routine cleaning and drying are useful parts of control.

If one bird in the home is suspected or confirmed to have bornavirus, talk with your vet about testing strategy for the other birds. Repeated PCR testing may be recommended rather than relying on one negative result. Avoid sharing dishes, toys, or cleaning tools between isolated and non-isolated birds unless they have been thoroughly cleaned and disinfected.

Prevention also means monitoring. Weigh your conure regularly on a gram scale, watch droppings closely, and take appetite or behavior changes seriously. Early veterinary attention gives your bird the best chance for supportive care and helps protect other birds in the household.