As with humans, diagnosis of fungal infections in animals is a significant hindrance to successful treatment. Diagnostic tests for galactomannan, regularly used in humans, have been found useful in the diagnosis of feline aspergillosis. Most cases do require imaging tests to determine if signs of certain infections are present, such as aspergilloma.
In the UK there are only seven licensed antifungal drugs for veterinary use, a number much smaller than those available to humans for dermatological and systemic fungal infections. The only systemic antifungal available for veterinary use is griseofulvin, effective only against dermatophytes, and even that is only registered for use in cattle and horses. For regular pets such as cats and dogs, there are several drugs to treat skin infections but none licensed to treat systemic infection.
So how do veterinarians treat diseases such as nasal or invasive aspergillosis in common pets like cats and dogs? They have to use drugs licensed in humans but off-license in animals, including the triazole drugs such as itraconazole and drugs such as amphotericin B. Similar to human use, these drugs must be monitored even more carefully given their unregulated nature in animals. If the disease is limited to the nasal sinuses, often surgical procedures are used in addition to antifungal drug treatment.