Adenoviruses are highly environmentally resistant viruses that often cause illness of the gastrointestinal tract and liver. This virus, which is also referred to as Atadenovirus, "wasting disease," or "star-gazing disease," has been known to spread to the kidneys, brain, and bone marrow in reptiles.
Within reptiles, each adenovirus tends to infect only one species or group (i.e., cross-infection and zoonosis are not likely). Bearded dragons have a very high chance of having this disease. Transmission is not completely understood, but definitely includes fecal-oral routes, and transmission from mother to offspring. It presents the most danger to very young, very old, or otherwise immune compromised patients. Unfortunately, the virus is never really cleared from the animal, so positive animals can shed the virus for life, potentially giving it to other members of the species. Healthy carrier adults may show no clinical signs whatsoever.
Clinical signs of adenovirus in affected reptiles include:
- Failure to thrive
- Anorexia & weight loss
- Green feces or urates
- Hind leg weakness
- Abnormal postures
- Neurologic deficiencies
- Parasite or bacterial infections that will not go away
- Sudden death
While many of these symptoms are not unique to this virus, these clinical signs warrant consideration of this virus as a potential cause of ongoing disease.
Testing involves a swab of the oral surfaces, cloacal surfaces and feces being sent to an outside lab for PCR testing (which looks for virus DNA). Results usually return in 7-10 days. At this point in time, there is no need to retest a negative patient unless it comes into contact with a "status unknown" or "positive" bearded dragon. Positive animals can lead a very productive life, but should be kept apart from negative animals.
There is no vaccine for any reptile adenovirus. Treatment in patients showing signs of illness consists of supportive care, including: fluid therapy, assist feeding, liver support medications, anti-inflammatory medication, and (if available) anti-viral medications such as oseltamvir (Tami-Flu). Increasing vegetables in the diet may help as well. Again, it presents the most danger to very young, old, or otherwise immune-compromised patients. If you are considering getting a bearded dragon as a pet, try to get one that is over 3-6 months old.
We currently recommend that all bearded dragons get tested for adenovirus infection, whether or not they are showing signs of illness. We also require adenovirus testing for any boarding bearded dragon. Patients that have a sample in "testing status" can be boarded in isolation at no additional charge until the test results return. For other reptile species, testing should be considered if signs of illness are occurring and anti-biotic therapy has been unsuccessful.
Dr. Wallace Stark joined the Animal House of Chicago veterinary team in 2012. He has a special interest in exotic animal medicine.