Caprine mastitis due to aspergillosis and zygomycosis: a pathological and immunohistochemical study

Of 73 goats on a dairy farm, 27 developed mycotic mastitis in the post-partum period. Purulent mammary secretion, progressive induration of the affected glands, slight fever and weight loss were observed. As treatment produced no improvement within 2-3 weeks, all diseased animals were slaughtered. At post-mortem examination, widespread acute and chronic mycotic lesions were seen throughout the affected glands. Infection was thought to have spread through the milk ducts as an ascending infection resulting from prophylactic intramammary treatment with antibiotic before parturition. In all lesions, aspergillus hyphae were identified by indirect immunofluorescent labelling, which gave a strong and uniform reaction with polyclonal and monoclonal antibodies to Aspergillus fumigatus. In a single granulomatous lesion, zygomycotic hyphae were also identified immunohistochemically. At terminal swellings of aspergillus hyphae, "yeast-like bodies" were produced, a phenomenon which seems to be associated with special, but unknown, circumstances.