Dr. Starks talks this month about Avian Bornavirus.
Avian Bornavirus (ABV) is a progressive and often fatal disease that causes neurologic symptoms in birds. It is ubiquitous and approximately 1/3 of companion parrots are infected with the virus. Although prevalence is high, most parrots are asymptomatic carriers and not all of these infected birds will demonstrate signs or become ill. Until recently recognition and diagnosis of ABV in parrots was rare. In 2008, ABV was identified as the causative agent for Proventricular Dilation Disease (PDD). PDD, also known as “Macaw Wasting Disease,” is the most prevalent manifestation of disease with parrots showing classic gastrointestinal signs of undigested food in feces, regurgitation, delayed crop emptying, diarrhea, and severe chronic weight loss.
Below are some key points to know about this disease
ABV infection is not limited to parrots. This disease was initially tied to new world parrots like macaws, but has since been recognized in waterfowl, ratites, and raptors.
ABV transmission is not well understood and it is generally accepted that the virus is transmitted through a fecal – oral route. Recent studies suggest that this virus is often spread from parents to chicks, and possibly through eggs. While this is a contagious disease, observation in ABV infected aviaries show that this virus does not spread rapidly throughout a flock. ABV is an RNA virus, and as a general rule, RNA viruses are unstable outside of the host and break down rapidly due to naturally occurring enzymes. This means that if you have a multi bird household with an ABV positive parrot with clinical signs, there is a chance that your other birds can remain free of the disease with appropriate preventative veterinary care and good husbandry.
Because this virus has an affinity for nerve tissue, signs of ABV vary significantly. Any neurologic parrot – those having difficulty perching, walking, flying, or abnormal limb/ head positions should consider testing for ABV. In addition, because ABV is considered to be the cause of PDD, any bird with unresponsive, chronic diarrhea, regurgitation, or ravenous appetite with weight loss should also consider testing. It is important to note that most parrots show very vague forms of the aforementioned signs, and are commonly missed by most owners.
There is no standard treatment for ABV. Most veterinarians use non-steroidal anti-inflammatory drugs like meloxicam or celecoxib to reduce neurological signs. Other medications may be used to treat diarrhea, secondary infections, and regurgitation.
Prevention and being proactive is key; ask your breeder or pet store if they have tested their birds for ABV. Quarantine any new birds for 30-45 days in a separate room before introducing them to your current flock. Most importantly, remember to contact your veterinarian for advice or questions concerning ABV.
Presence of Avian Bornavirus RNA and Anti-avian Bornavirus Antibodies in Apparently Healthy Macaws. Siwo R. De Kloet and Gerry M. Dorrestein. Avian Diseases Digest 4(4):e10-e11. 2009.
Proventricular Dilatation Disease in Cockatiels (Nymphicus hollandicus) After Infection With a Genotype 2 Avian Bornavirus . Negin Mirhosseini, MS, Patricia L. Gray, DVM, MS, Sharman Hoppes, DVM, Dipl AVBP (Avian), Ian Tizard, BVMS, ACVM (Honorary), H. L. Shivaprasad, BVSc, PhD, ACPV, and Susan Payne, PhD. Journal of Avian Medicine and Surgery September 2011 : Vol. 25, Issue 3 (Sep 2011), pg(s) 199-204
Vertical Transmission of Avian Bornavirus in Psittaciformes: Avian Bornavirus RNA and Anti-Avian Bornavirus Antibodies in Eggs, Embryos, and Hatchlings Obtained from Infected Sun Conures (Aratinga solstitialis). Anelle Kerski, Arne H. de Kloet, and Siwo R. de Kloet. Avian Diseases Digest 7(3):e9-e10. 2012.