Odontogenic dysplasia in the molar teeth of Steppe lemmings (Lagurus lagurus).

In a colony of Steppe lemmings (Lagurus lagurus), of the rodent sub-family Arvicolinae, 8.6% of animals exhibited dysplastic growth of the molar teeth. Clinical findings included nodular swellings of the mandible, hypersalivation, malocclusion and emaciation. To investigate the underlying cause, two control and 10 affected animals, aged between 6 and 18 months, were examined using radiography and computed tomography and at post mortem examination. Bilaterally symmetrical masses were identified in the molar regions of the left and right mandible and maxillae. Histologically, the masses were characterised by dysplastic odontogenic epithelium, dentin, cementum, enamel and dental pulp formation that resembled odontogenic dysplasia. This tumour-like proliferative lesion has been reported in the continuously-growing incisor teeth of ageing rodents and lagomorphs but this is the first description of the clinico-pathological features of such odontogenic dysplasia of the molar teeth of Steppe lemmings.

Animal sexual abuse in a female sheep.

A case of animal sexual abuse and sadism in a female sheep is described. The animal suffered severe genital tract injury most likely caused by the insertion and manipulation of a branch of wood and by penile penetration by a human male. Postmortem examination revealed multiple perforations of the vagina with massive haemorrhages. Animal sexual abuse is a complex diagnostic problem in veterinary medicine. Reported cases are often linked to sadism and often lead to the animal's death. Veterinarians should keep in mind animal sexual abuse as a differential diagnosis in cases of anogenital injuries of unknown origin.

In vitro characterization and preferential infection by canine distemper virus of glial precursors with Schwann cell characteristics from adult canine brain.

AIMS: Canine distemper virus (CDV)-induced demyelinating leukoencephalomyelitis is a naturally occurring model for multiple sclerosis. The aim of this study was to establish primary glial cell cultures from adult canine brain for the analysis of CDV spread and cell tropism. METHODS: Cultures were inoculated with the CDV-R252 and a CDV-Onderstepoort strain expressing the green fluorescent protein (CDV-OndeGFP). CDV antigen expression was studied using cell type-specific antibodies at different days post infection. Glial cells expressing p75(NTR) were purified using antibody-based techniques and characterized with regard to antigen expression and proliferation. RESULTS: Three weeks after seeding, cultures contained spindle-shaped cells expressing p75(NTR), oligodendrocytic cells, astrocytes, microglia and fibroblasts. Both CDV strains induced a mild to moderate cytopathic effect that consisted of single necrotic and few syncytial giant cells, but displayed in part a differential cell tropism. Whereas CDV-OndeGFP expression in microglia and astrocytes did not exceed 1% and 50%, respectively, CDV-R252 infected 100% and 80% of both cell types, respectively. The cells most early infected by both CDV strains expressed p75(NTR) and may correlate to cells previously identified as aldynoglia. Treatment of p75(NTR+) cells with Schwann cell mitogens and serum deprivation increased proliferation and A2B5 expression, respectively, indicating common properties compared with Schwann cells and oligodendrocyte precursors. CONCLUSIONS: Infection of adult canine astrocytes and microglia revealed CDV strain-specific cell tropism. Moreover, this is the first identification of a glial cell type with Schwann cell-like properties in adult canine brain and, more importantly, these cells displayed a high susceptibility to CDV infection.