A new, non-Invasive technique recently described for the treatment of canine nasal aspergillosis was performed on four dogs. The antimycotic agent used was a 10 per cent enilconazole suspension, with the drug left in situ for a period of one hour. None of the dogs responded to single treatment. One dog died from an acute septic response secondary to pyelonephritis and bacterial endocarditis eight days after a second treatment. A second dog responded completely to a second treatment and remained free of fungal disease for a follow-up period of H months. In the remaining two dogs, extensive and profuse fungal growth was seen on rhinoscopic reexamination. Conventional treatment, with tube Implantation into the frontal sinuses and nasal irrigation for two weeks, was performed. Successful resolution of infection was obtained. Although the new, non-invasive technique was simple to carry out and well tolerated by the dogs, instillation of 10 per cent enilconazole appears to have poor therapeutic efficacy and exacerbated fungal growth in two of the animals.