Invasive Species Compendium

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Abstract

Further observations on the testicular pathology in Trypanosoma vivax infection of sheep and goats.

Abstract

Trypanosoma vivax infection in 13 rams and 14 goats was associated with mild to severe testicular degeneration, which was correlated with seminiferous tubular diameter and epithelial thickness in sheep; the duration of disease was not correlated with these changes in either species. The degree of testicular degeneration determined the numbers of spermatozoa in the epididymis, with total disappearance of spermatozoa in the most severe cases. In goats spermatogenic cells were usually defoliated in large numbers into the lumen of the seminiferous tubules, with appearance of the degenerate cells in the epididymal tubules. The degeneration was presumed to result from the pyrexia that accompanied the numerous parasitaemic peaks, a hypothesis supported by focal alopecia of the scrotal skin and absence of trypanosomes (and hence inflammatory reaction) in the intertubular connective tissue. A second mechanism of degeneration was the appearance in two sheep of fibrin thrombi in testicular vessels accompanied by testicular degeneration and generalised mononuclear cell reaction; one of these thrombi virtually blocked the channels of these vessels resulting in pooling of blood with distension of the vessels and resultant infarction of the entire seminiferous epithelium in many parts of the testes.