In 12 cases of lethal acrodermatitis (LAD), four sampling techniques (brush, swab, scrape and adhesive tape strip) were used to study the distribution of yeasts in various body sites and these results were compared with those from five cases of atopic dermatitis and those of 10 normal dogs. Malassezia was frequently isolated from lesional and non-lesional skin and haircoat, footpads, nails and mucous membranes from dogs with either LAD or atopic dermatitis, although, generally, more Malassezia organisms were isolated from LAD cases. In normal dogs, Malassezia was most frequently recovered from the ear canal and the perianal skin. Candida was isolated frequently from dogs with LAD, but only a single isolate of this yeast was found in the other two groups. Fungal hyphae and pseudohyphae, probably Candida albicans, could be detected in samples collected from the nails and footpads of dogs with LAD. Both Malassezia and Candida could be isolated using all four sampling techniques. The MacKenzie (toothbrush) technique and adhesive tape strip cultures proved simple methods for the semiquantitative evaluation of yeasts. The high recovery rate of Malassezia and Candida from dogs with LAD is probably related to immune dysfunction, particularly T-cell dysfunction, known to be present in these dogs. C albicans infection may in part be responsible for the pathogenic changes of the nails and footpads commonly seen in cases of LAD.