Inclusion Body Disease
Inclusion Body Disease (IBD) is the one word which strikes fear into the hearts of all boa and python keepers as it is incurable and ultimately always leads to death. It is also a very unpleasant illness causing great suffering in the snake before death or humane euthanasia. Unfortunately, as there is currently no treatment for this disease, the best weapon is prevention.
What is Inclusion Body Disease?IBD is believed to be caused by a retrovirus and seems to affect only members of the “boid” family, i.e. pythons and boas. It affects the two groups of snakes in different ways but in both cases, the condition is always fatal once the snake begins exhibiting symptoms of the disease. Snakes can also be asymptomatic but still be carriers of the disease – boas, for example, often harbour the virus without exhibiting any symptoms. Thus, if a snake that is housed with other infected snakes is not showing any symptoms, this does not necessarily mean that it is immune to the disease – and it can still be a source of infection for other, new snakes.
The disease is believed to be caused by “inclusion bodies” (a type of retrovirus) which have been identified in the epithelial cells of the kidneys and pancreas of affected snakes. It has also been associated with neuronal degeneration and lesions in the spinal cord and brain, which may then lead to myelin degeneration and nerve damage. In addition, the spleen often becomes grossly atrophied and fribrosed. In some cases, snakes infected with IBD have also been found to be infected by the snake mite, Ophionyssus natricis, but as this parasite is not present in all cases of the disease, a definitive causal link cannot be established.
What are the Symptoms?Pythons and boas exhibit slightly different symptoms, with the disease developing more slowly in the latter. Infected boas are often struck with disorders of the nervous system such as the inability to right itself when turned over, “star-gazing”, inability to strike or constrict – or even just full-on paralysis. Boas can also show extreme weight loss and suffer from chronic regurgitation, as well as respiratory infections.
IBD is more aggressive in pythons which, in addition to the symptoms described for the boas, also suffer from “mouth rot” (infectious stomatitis), disorientation and loss of muscle coordination and reflex responses that are heightened or exaggerated.
In both, the disease is particularly rapid and fatal in juveniles, where death quickly follows the onset of flaccid paralysis.
Prevention is Better than CureBecause it is highly contagious (and always fatal) the best course of action upon discovering the disease is euthanasia. Even if the snake can be kept alive for a period of time, by supportive measures such as force-feeding and hydration, it is only prolonging the animal’s suffering as the damage to the nerves, brain, spinal cord and internal organs is so extensive, there is no chance of recovery and only decreasing quality of life for the reptile.
As there is no cure (other than euthanasia), prevention really is the only hope. IBD is believed to be spread by viral transmission so the following may all contribute to the disease:
- Housing infected individuals with healthy snakes (contact with infectious organisms)
- Transmissions through airborne aerosolised secretions
- Poor hygiene and indiscriminate handling (transmissions through keeper passing infection from one snake or enclosure to another)