Officially named in 2008, Avian Bornavirus has become a worry among every educated parrot owner. Questions like ‘How do I prevent it?’ and ‘What causes it?’ are abundant. And then there is the sad one of ‘Now what?’ when someone finds their bird infected.
ABV was first seen in parrots in 2008. It is one of several strains of Borna virus, which can also be found in cats, dogs, horses, sheep, foxes and other animals. The virus can cause the bird’s immune system to over-respond, damaging the digestive system. This over-reaction is what causes Proventricular Dilation Disease
The worry comes from the knowledge that ABV can cause PDD. PDD is much more devastating than ABV. Both are viruses and there is no cure for them as of yet. There also is no vaccine for them. The truth is ABV is not necessarily a death sentence. In fact, birds can carry and shed the virus, but live an otherwise healthy life.
PDD is the result of the dilation of the proventriculus. PDD causes paralysis in the upper intestine. This prevents the food from moving through the digestive tract. The nutrients are not absorbed and the bird dies of starvation and secondary inproper nutrition. It is a devastating disease and Dr. an Tizzard, DVM, Ph.D says that if theory is correct, vaccines may not work, but that it does not mean it should not be tried.
Things to look for if you suspect PDD can begin with seizures. These often show before gastric upset becomes evident. One sign that is certain will be the passing of undigested food in droppings. Other signs include massive weight loss, ataxia, paralysis, head tremors, and inability to perch. If you suspect your bird has PDD, contact your vet and isolate the bird immediately.
There are no real symptoms of ABV. There are, however, tests. Initially, fecal tests were performed, but the virus is not always shed constantly. It can be shed intermittently, so this was not a reliable test method. Now, blood tests are done to detect ABV. Though there are ABV tests, there is no test for PDD. A positive ABV result does not necessarily mean a positive PDD result, making testing for the disease difficult.
ABV and PDD are transferred by close contact with infected birds and feces in which the virus is shed. If you have birds in close proximity of one another or that share play stands, the other birds should be tested. A biopsy of the crop may be able to confirm PDD. After isolating the bird(s) you suspect are infected, you should disinfect the area. Mixing one part bleach with 50 parts water and a small amount of dish soap will disinfect the area well. This can be used on cages and play gyms and play stands. Avoid sharing toys with non-infected birds to avoid transfer to healthy birds.
ABV can be passed from a hen to her babies through the egg. This sounds worse than it might be. Since babies’ immune systems would not recognize the virus, there would be no response, and therefore, no over-response. The babies would, in effect, become healthy carriers of ABV, according to Dr. Tizzard. In theory, they would not develop PDD, but would still shed the virus.
PDD is currently being treated with anti-inflammatory and immuno-suppressants, but these only extend the life of the bird. A vaccine is being worked on with the hopes that it will have an effect. Treatment for PDD is in the very early stages and there is still much research to do.
PDD and ABV are two separate viruses. Having one does not mean having the other. In fact, other conditions can mimic PDD, such as heavy metal poisoning, E. coli, mega bacteria and foreign body ingestion. Making sure the test results are accurate is crucial. By the time a bird starts showing signs of illness, so waiting to see if things turn around could be dangerous. The turn taken could prove fatal.