Pulmonary botryomycosis secondary to septic funiculitis in a pony

Botryomycosis is a rare, chronic, and pyogranulomatous disease characterized by abscesses formation, often caused by Staphylococcus aureus and occasionally other bacteria. The present paper reports epidemiologic, clinical, laboratorial, and pathologic findings in a pony with pulmonary botryomycosis secondary to septic funiculitis. A 10-year-old male pony, castrated 90 days earlier, with a large mass on the inguino-scrotal region, was evaluated. The mass had 23.5 × 14.6 cm size and presented multiple firm and nodular elements among fibrotic tissue and several draining tracts with purulent discharge containing gray opaque grains. Hematology revealed severe leukocytosis by neutrophilia and lymphocytosis. Serum biochemistry profiles showed hyperproteinemia by hyperglobulinemia and slight increase of gammaglutamyl transferase activity. At necropsy, the inguinal mass presented whitish and dark reddish multifocal areas with multiple small abscess surrounding the spermatic cords and inguinal rings. The lungs showed reddish multifocal nodules with the same characteristics observed in the inguinal mass. Inguinal mass and lungs microscopic evaluation showed marked proliferation of connective fibrous tissue interspersed by many macrophages, neutrophils, and multinucleated giant cells surrounding multifocal to coalescent Splendore-Hoeppli phenomenon areas within myriads of coccoid Gram-positive bacteria in botryoid arrangements. Cutaneous botryomycosis and bacteria hematogenous spread, causing secondary pulmonary botryomycosis, could be considered an infected wound complication and might be avoided with basic presurgical antisepsis and antimicrobial therapy.