Testicular and epididymal pathology in Yankasa rams experimentally infected with Trypanosoma congolense

Objective: To investigate the pathological effect of experimental Trypanosoma congolense (T.\udcongolense) infection on the testes and epididymis of Yankasa rams.\udMethods: Nine intact un-castrated rams were obtained and divided into 2 groups of 6 infected\udwith 1伊106 T. congolense and 3 uninfected controls. Four infected and one uninfected control rams\udwere sacrificed on Day 75 post infection and the remaining four rams (two each of infected and\udcontrol groups) on Day 86 post infection.\udResults: All infected rams became parasitaemic within 7-11 days post infection with clinical\udtrypanosomosis characterized by peri-orbital oedema and a transient period of scrotal oedema,\udthis was followed by progressive decrease in scrotal size. At postmortem, the organs from infected\udrams were pale and emaciated but no observable lesion was seen in the uninfected control\udgroup. At histology, the testes showed areas of necrosis on the interstitial tissue characterized by\uddestruction of cellular structures within the tissues and seminiferous tubules. There was moderate\udto severe testicular degeneration manifested by loss of tissue architecture and infiltration with\udmacrophages, neutrophils, lymphocytes and plasma cells. Fibrous connective tissues were\udalso seen in the testes of the infected rams indicative of replacement of normal cells by fibrous\udconnective tissue. The epididymis of the infected rams had collection of some spermatocytes and\uddesquamated epithelial cells in the epithelial ducts although others were devoid of spermatocytes\udin their ducts leading to loss of epididymal sperm reserves. However, these were not seen in the\uduninfected control rams.\udConclusions: T. congolense causes testicular and epididymal damage which may render the\udrams infertile or sterile