all infected snakes may regurgitate. Boas lose weight and may develop clogged nares (nostrils), stomatitis, or secondary pneumonia. The disease can rapidly progress to produce nervous-system disorders, such as disorientation, corkscrewing of the head and neck, holding the head in abnormal and unnatural positions, rolling onto the back, or stargazing. Stomatitis, pneumonia, undifferentiated cutaneous sarcomas, lymphoproliferative disorders, and leukemia have all been observed in affected specimens. Burmese pythons generally show signs of central nervous system disease without manifestation of other clinical signs and regurgitation is seen only in boas. These are symptoms similar to those seen in specimens infected by Chlamydia–specifically Chlamydophila psittaci, the so-called parrot's disease. Several snakes have been seen with proliferative pneumonia, while inclusions are commonly seen in the liver, kidney, and pancreas. Cases have also been observed with only very few inclusions. In a few snakes with signs of central nervous system disease, and with a severe encephalitis, no inclusions have been seen in any cells. While the presence of characteristic inclusions is diagnostic for the disease, the absence of such inclusions does not necessarily indicate that the snake is not diseased or is free from the IBD virus. While cells having inclusions may show mild degenerative changes, inflammation is rarely seen in visceral tissues. In the brain, mild to severe encephalitis occurs, with lymphocytic perivascular cuffing. Several snakes with lymphoproliferative disorders have been identified with lymphoid infiltrates in multiple organs. Laboratory diagnosis The disease can be diagnosed in live snakes through blood tests. Primary route of transmission The primary route of transmission has not yet been identified, but direct contact may result in its transmission to developing embryos in viviparous species and eggs in oviparous species. Venereal transmission is also indicated as a possibility. The snake mite, Ophionyssus natricis, has been implicated as a possible vector for the virus, since mite infestations are commonly seen in epizootics of IBD and in captive specimens of these snakes. Mites are sometimes very difficult to eradicate due to their resistance to certain toxins used to eliminate them. Permethrin is effective against mite infestations, but must be used with great caution and only in small quantities due to its toxicity to snakes. Alternative approaches include biological agents that are sprayed onto infested animals that desiccate the mites, rendering them unable to lay their eggs or consume blood beneath the scales of their host. The incubation period for mite eggs