Twelve goats about 3 months of age were divided into 4 equal groups. Goats in Groups 1 and 2 were infected with orf virus followed by Corynebacterium pyogenes infection of Groups 1 and 3, 3 days after the first appearance of orf lesions. Goats in Group 4 were uninfected controls. Complicated orf lesions which consisted of wet suppurative scabs around the entire lips were observed in goats in Group 1. The lesions persisted for 24 days but were most severe from days 8 to 13. Goats in Group 2 developed lesions typical of orf virus infection that lasted 10 days, while goats in Group 3 developed small nodules of about 1 cm diameter, 48 hours following the introduction of C. pyogenes, which persisted for only 6 days. No lesion was observed in goats in Group 4. Two goats in Group 1 with complicated orf died after 16 and 22 days respectively.
Caseous lymphadenitis is an infectious disease of almost all animals, particularly small ruminants that are caused by Corynebacterium pseudotuberculosis. The organism causes the formation of suppurative abscesses in superficial and visceral lymph nodes and in visceral organs. This current study was designed to elucidate the clinicopathological responses and PCR detection of the aetiological agent in the vital organs of goats challenged with C. pseudotuberculosis and its immunogenic mycolic acid extract. A total of twelve clinically healthy crossbred Boer female goats were divided into three groups: A, B, and C (four goats per group). Group A was inoculated intradermally with 2 ml of sterile phosphate buffered saline (PBS) pH 7 as a control group. Group B was inoculated intradermally with 2 ml of mycolic acid extract (1 g/ml), while group C was inoculated intradermally with 2 ml of 10⁹ colony-forming unit (cfu) of live C. pseudotuberculosis. The experimental animals were observed for clinical responses for 90 days post-inoculation and the clinical signs were scored according to the severity. The clinical signs observed in this study were temperature, heart rate, respiratory rate, rumen motility, enlargement of lymph nodes, and body condition score. The experimental animals were euthanised and tissue samples from different anatomical regions of the vital organs were collected in 10% buffered formalin, processed, sectioned, and stained with H&E. Results of both C. pseudotuberculosis and mycolic acid treated groups indicated a significant difference (p