MORPHOLOGY OF SPERMATOZOA IN THE CAUDA EPIDIDYMIDIS BEFORE AND AFTER ELECTROEJACULATION AND A COMPARISON WITH EJACULATED SPERMATOZOA IN THEDOMESTIC CAT

When 2 ejaculates are collected by electroejaculation from the domesti c cat within a period of 10 min the first ejaculate has a higher propo rtion of abnormal spermatozoa than the second. The reason for this dif ference is not known for the domestic cat, but in other species long-t erm epididymal storage results in a higher proportion of abnormal sper matozoa. The aims of this study were to determine the proportions of a bnormal spermatozoa in the cauda epididymidis and to ascertain if elec troejaculation affects this proportion. Therefore the proportions of s permatozoa in the cauda epididymidis with different morphological abno rmalities were compared before and after ejaculation. In addition, the proportion of morphologically abnormal spermatozoa in the epididymis was compared with that in the ejaculate. Nine privately-owned domestic cats were anesthetized, and one testicle was surgically removed. An e jaculate was collected by electroejaculation, after which the remainin g testicle was ectomized. There were no significant differences in the proportions of different sperm abnormalities between the cauda epidid ymidis removed before ejaculation and the one removed after ejaculatio n. A significantly (P=0.009) higher proportion of spermatozoa with tai l abnormalities was found in the ejaculates compared with the cauda ep ididymides (11.1 and 1.6%, respectively), while, as expected, there wa s a lower proportion of spermatozoa with distal droplets in the ejacul ates than in the cauda epididymides (35.1 and 75.9%, respectively). Th is new information contributes to the understanding of the etiology of sperm defects in the domestic cat, and is of importance when evaluati ng a semen sample in this species. (C) 1998 by Elsevier Science Inc.