[Neuropathology of experimental toxocariasis in Syrian golden hamsters]

Toxocariasis is a disease caused by a larval stage of Toxocara sp., and predominantly involves Toxocara canis and Toxocara cati. Toxocara larve tend to accumulate in the brain tissue and can remain alive and motile for years, producing a different neuropathological damage. Very little information is available on toxocariasis in the hamster. The aim of this study was to investigate a neuropathologic characteristic of experimental toxocariasis in hamsters.

The research included 15 Syrian golden hamsters (10 experimental and 5 control). The animals from experimental group was given about 10,000 ags of T. Canis intraorally by gavage. The experimental animal was sacrificed in moribund state after two (3 animals), three (3 animals), and five weeks (4 animals) of inoculation. The brains of both the experimental and control animals were removed from the scul and were histologically analised using hematoxylin & eosin, Walton stain, and May Grunwald Giemsa.

Histopathologically, the cerebellum was the most affected area, but we can also see the migrating larve in every other part of the brain. The loss of Purkinje cells, glial nerve fibres and nerve sheaths were characteristic and common findings. We found granulomatous lesions with migrating larvae in the center, but larvae and lesions also existed independently, suggesting that some of the degenerative changes might be the result of indirect effects of the larvae. We also found haemorrhagic lesions and exudative lesions with or without migrating larvae. The white exudative lesions around the vessel walls suggest vasculitis consisting of eosinophils and lymphocyte infiltration. We also found area of gliosis and haemosiderosis. All animals had intensive meningitis.

Because of specific neuropathological evidence, we suggested that the experimental infection of hamsters may be a useful model of toxocariasis in humans.