PDS, which is short for Proventricular Dilatation Syndrome, causes regurgitation, weight loss, and death in macaws and other parrots.  This condition has recently been linked with a poorly understood virus known as bornavirus. Bornavirus has been linked with feather-plucking, toe-tapping, and other conditions in parrots. 

Bornavirus appears to be widespread in captive parrot populations. Bornavirus has been detected in canaries and is likely to be found in other species of birds. Unfortunately the tests to detect  bornavirus in live birds are not 100% accurate. Live birds may test negative by some tests yet still have the disease confirmed by post-mortem tests. This means that seemingly healthy birds are infected with bornavirus and capable of spreading it to other birds. Complicating this situation is that not every bird that tests positive for bornavirus will develop illness which is why it goes undetected in many healthy birds.

Can We Treat This Disease?

While there are treatments that may provide temporary relief in some birds, there is no cure that will eliminate the bornavirus. Some birds succumb quickly while others may survive months or years after diagnosis. Once a bird is diagnosed with bornavirus, it must be managed in ways that prevent it spreading the infection to other birds.  Special attention is needed for ill birds. They need a balanced diet, access to ultraviolet-B light or natural sunlight and proper photoperiods, extra warmth, regular misting or showering, and regular check-ups by a veterinarian to detect signs of other infections early. Some PDD birds do better while on medications like celecoxib, an anti-inflammatory. Adding special enzymes to food may help reduce regurgitation and improve weight gain of some PDD birds. Bornavirus-infected birds may have yeast or bacterial infections that will respond to medical therapy, but eventually these opportunistic nfections may overwhelm the bird.  At that point, your bird’s quality of life is declining.  The decision to euthanize a bornavirus-infected bird is not always easy.  However, if your bornavirus-infected bird is has frequent secondary infections, has lost a dangerous amount of weight, has uncontrolled neurological conditions, or its medications are losing effectiveness, then euthanasia should be considered. It’s important to discuss quality of life with your veterinarian, and with all the members of your family, so that you recognize when your bird is suffering. 

How Do We Protect A Bird From Bornavirus?

Bornaviruses do not last long outside of their hosts. First, clean cages, food and water bowls, toys, and perches in hot soapy water. Next, disinfect these items. Many common disinfectants, such as 1:30 or 1:50 chlorine bleach, inactivate the bornaviruses. Finally, rinse well in water to remove any trace of disinfectant.

Spot clean after your bird, picking up its droppings and disinfecting using a sanitizing hand-wipe containing bleach or benzalkonium chloride. Clean and disinfect grooming tools between birds.  Wash your hands in hot soapy water or with a sanitizing hand gel before you handle other birds.

Good hygiene along with disinfection should reduce the risk of transmission.

Can We Prevent PDD and Bornavirus?

We don’t know enough to prevent the disease. Any time you have birds there are risks of becoming infected with different diseases. Unfortunately, bornavirus infection is difficult to detect. Carrier birds may seem healthy yet are capable of spreading the infection to others. Signs of illness may take years to develop so it is often impossible to know when an infection started.