Systemic mycotic infections in cats

摘要

The systemic mycotic agents include a group of dimorphic fungi (Histoplasma capsulatum, Blastomyces dermatidis, Coccidioides immitis) that have specific regional geographic distributions. The dimorphic fungi occur as free-living mycelial forms in thesoil but convert to a parasitic form within the mammalian host. Infection occurs by inhalation of infectious particles from the soil. Failure of the host immune system to contain the infection in the pulmonary tree results in generalized dissemination to other body organs via blood and lymphatics. Direct cutaneous infection has been reported with Coccidioides, but is rare. Cryptococcus neoformans, is a saprophytic yeast with a worldwide distribution. Infection with this organism can occur by inhalationor direct cutaneous inoculation. As a species, cats are very susceptible to infection with Histoplasma and Cryptococcus, less susceptible to Blastomyces, and very resistant to infection by Coccidioides.