Infertility in a Maltese poodle as a result of a sperm midpiece defect.

A 2 1/2-year-old Maltese poodle was examined for breeding soundness following a series of unsuccessful matings to fertile bitches. He was found to have only 8% normal sperm in his ejaculate when Spermac-stained smears were examined under the light microscope. The defect most frequently encountered involved the midpiece attachment, and the various manifestations of disintegration found in this region are described and illustrated. Transmission and scanning electron microscopy confirmed light microscopical findings.