Treatment of equine phycomycosis by immunotherapy and surgery

Abstract

Treatment of equine phycomycosis with a vaccine derived from ultrasonicated hyphae of Hyphomyces destruens was attempted in 30 cases of clinical hyphomycosis, 10 cases of hyphomycosis following unsuccessful surgery and 5 cases of basidiobolomycosis. Approximately 53% of animals with clinical hyphomycosis were cured after vaccination, while a further 33% clinically improved. All horses with hyphomycosis treated within 2 weeks of unsuccessful surgery were cured. There was no response to vaccination with a Hyphomyces preparation in horses with basidiobolomyucosis, while surgery alone resulted in a cure of approximately 69%. Animals tolerated the vaccination procedures well. In all cases there was a moderate to severe reaction at the site of subcutaneous injection which subsided within 96 hours. In approximately 30% of injections a sterile abscess formed at the site but responded promptly to treatment. Response to vaccination at the site of the lesion was observed within 7 to 10 days of first injection. There was progressive reduction of pruritus, drying of the surface of the lesion, expulsion of kunkers, fibrosis of the granuloma, and eventually complete epithelialisation.