THE EFFECTS OF STAINS AND INVESTIGATORS ON ASSESSMENT OF MORPHOLOGY OF CANINE SPERMATOZOA

Percentage and types of morphological abnormalities found in canine sp ermatozoa were evaluated by three investigators using three stains (Gi emsa-Wright stain [Diff-Quik] eosin Y/nigrosin [Hancock] and eosin B/n igrosin [Society for Theriogenology morphology stain] with conventiona l light microscopy, compared to phase contrast microscopy on unstained samples. The percentage of spermatozoa with abnormal heads, midpieces , and tails varied by technique and by investigator Average percentage s of morphologically normal spermatozoa were significantly higher in s amples stained with Diff-Quik and samples examined by phase contrast m icroscopy than in samples stained with Hancock or Society for Therioge nology morphology stains. No effect of investigator on the percentage of morphologically normal spermatozoa was assessed, Results suggest th at staining or preparation technique may alter the morphology of canin e spermatozoa artifactually.