Invasive Colonic Entamoebiasis in Wild Cane Toads, Australia.

We detected a disease syndrome in free-ranging Australian cane toads involving atypical behavior and emaciation that is associated with a previously undescribed Entamoeba sp. that infiltrates the colonic lining, causing it to slough. The organism may become seasonally pathogenic when toads are under hydric and nutritional stress.

Impact of poxvirus lesions on saltwater crocodile (Crocodylus porosus) skins.

Cutaneous poxvirus infections are common in several crocodilian species and are of importance in crocodile farming due to their potential impact on the tanned hide. To confirm poxvirus infection and understand the impact on saltwater crocodile (Crocodylus porosus) skin, fourteen animals from different age groups (five hatchlings, five yearlings and four grow-outs) were selected based on a criterion of ten poxvirus-like lesions per animal. One lesion on each animal was extruded for genetic analysis and transmission electron microscopy. Both methods confirmed poxvirus so the remainder of lesions were re-examined every six weeks over a 24 week study period. Each lesion went through four distinct phases: early active, active, expulsion and healing. To understand how these lesions impact on the final skin product, one crocodile from each age group was euthanised and the lesions examined. Using standard skin grading techniques (light-table), the early phase (early active - expulsion) lesions were all translucent and would lead to downgrading of the skin or, at worst, rendering them unsaleable. At the later stages of healing, the translucency reduces. Histological examination of the phases confirm that the basement membrane is not breached by the infection further indicating that poxvirus lesions, given enough time, will eventually have no detrimental effect on skin quality. This is obviously dependent upon no more lesions developing in the interim.

Stress in farmed saltwater crocodiles (Crocodylus porosus): no difference between individually- and communally-housed animals.

Minimising stress in farmed crocodiles is not only important for improving animal welfare, but may also improve skin blemish healing and infection resistance, which influence the quality of the final skin product. Forty near-harvest size saltwater crocodiles (1.6-1.8 m TL) from two Australian farms were sampled to evaluate the effect of different pen types (communal pens n=20; individual pens n=20) on stress as indicated by plasma corticosterone. Blood samples were taken within three minutes of immobilisation and analysed using a commercial enzyme immunoassay kit. There was no relationship with animal size (P=0.16), between farms (P=0.86), pen types (P=0.69), communal pens between farms (P=0.28) or individual pens between farms (P=0.24). Based on corticosterone levels, it appears that individual pens do not cause significantly more stress on harvest-size animals than communal pens. Individual pens meet their design specifications by achieving comparable healing rates of belly skin blemishes as communal pens without compromising animal welfare and minimising the possibility of new blemishes.

Paramyxoviruses in reptiles: a review.

In 1972, an outbreak of neurorespiratory disease in a Swiss serpentarium formed the basis for the first description of a paramyxovirus isolated from a reptile. In the forty years since this outbreak, there have been over 50 published reports about reptilian paramyxoviruses from all over the world. The majority of these investigations have concerned themselves with ferlaviruses (sometimes previously referred to as ophidian paramyxoviruses, or OPMV). The biology of these viruses is reviewed and this is followed by a review of the clinical findings that are associated with ferlaviral infection and the various diagnostic tests that are used to identify infected reptiles. Recently, a second, and highly divergent, reptilian paramyxovirus, Sunshine virus, was described in Australian pythons, so it is an opportune time to reflect on the paramyxoviruses that infect reptiles.

Sunshine virus in Australian pythons.

Sunshine virus is a recently discovered novel paramyxovirus that is associated with illness in snakes. It does not phylogenetically cluster within either of the two currently accepted paramyxoviral subfamilies. It is therefore only distantly related to the only other known genus of reptilian paramyxoviruses, Ferlavirus, which clusters within the Paramyxovirinae subfamily. Clinical and diagnostic aspects associated with Sunshine virus are as yet undescribed. The objective of this paper was to report the clinical presentation, virus isolation, PCR testing and pathology associated with Sunshine virus infection. Clinical records and samples from naturally occurring cases were obtained from two captive snake collections and the archives of a veterinary diagnostic laboratory. The clinical signs that are associated with Sunshine virus infection are localised to the neurorespiratory systems or are non-specific (e.g. lethargy, inappetence). Out of 15 snakes that were infected with Sunshine virus (detected in any organ by either virus isolation or PCR), the virus was isolated from four out of ten (4/10) sampled brains, 3/10 sampled lungs and 2/7 pooled samples of kidney and liver. In these same 15 snakes, PCR was able to successfully detect Sunshine virus in fresh-frozen brain (11/11), kidney (7/8), lung (8/11) and liver (5/8); and various formalin-fixed paraffin-embedded tissues (7/8). During a natural outbreak of Sunshine virus in a collection of 32 snakes, the virus could be detected in five out of 39 combined oral-cloacal swabs that were collected from 23 of these snakes over a 105 day period. All snakes that were infected with Sunshine virus were negative for reovirus and ferlavirus by PCR. Snakes infected with Sunshine virus reliably exhibited hindbrain white matter spongiosis and gliosis with extension to the surrounding grey matter and neuronal necrosis evident in severe cases. Five out of eight infected snakes also exhibited mild bronchointerstitial pneumonia. Infection with Sunshine virus should be considered by veterinarians investigating disease outbreaks in snakes, particularly those that are associated with neurorespiratory disease.