Diagnosis of canine nasal aspergillosis by cytological examination: a comparison of four different collection techniques.

OBJECTIVES To compare the efficacy and diagnostic value of four different sample collection techniques for cytological identification of nasal aspergillosis-penicilliosis in dogs. METHODS Fifteen dogs with a history of persistent nasal discharge and clinical and radiographic findings suggestive of aspergillosis were evaluated using four different cytological sampling techniques. These were a direct smear from the nasal discharge, blind swab collection under general anaesthesia, brushing from suspect lesions under direct endoscopic visualisation and a squash technique of mucosal biopsies from suspect lesions obtained under direct endoscopic visualisation. RESULTS Direct smear collection and blind swab collection detected fungal hyphae in 13.3 and 20 per cent of examined cases, respectively; brush samples detected fungal hyphae in 93.3 per cent and fungal spores in the 45 per cent of examined cases and squash samples detected fungal hyphae in 100 per cent and fungal spores in 36 per cent of examined cases. CLINICAL SIGNIFICANCE This study confirmed the high accuracy of cytology samples in the diagnosis of nasal aspergillosis-penicilliosis when collected under direct endoscopic visualisation and showed the poor value of samples that were collected by blind swabs or prepared from samples of nasal discharge.