REPRODUCTIVE ASSESSMENT OF MALE ELEPHANTS (LOXODONTA-AFRICANA AND ELEPHAS-MAXIMUS) BY ULTRASONOGRAPHY

Transrectal ultrasonography was performed on five wild and two captive male African elephants (Loxodonta africana) and four captive male Asi an elephants (Elephas maximus) to develop standards for assessment of reproductive health and status. The entire internal urogenital tract w as visualized ultrasonographically by using a 3.5 MHz or a 7.5-MHz tra nsducer in combination with a probe extension adapted for elephant ana tomy. The findings were verified by postmortem ex situ ultrasound exam inations in several individuals of each species. Each part of the inte rnal urogenital tract was sonographically detectable except for the bu lbourethral glands and the cranial portion of the ureters and ductus d eferentes, which were only observed in situ in the neonate. Each struc ture visualized was measured and described. The size and morphology of the urogenital structures, especially the accessory glands, were indi cative of breeding status, if known. There was a notable difference be tween African and Asian males in the size and morphology of the prosta te gland and a slight difference in the shape of the ampullae. No othe r structure showed significant species differences. The detection of t he location and description of the testes may provide information for modifying present castration procedures. Furthermore, ultrasound exami nation of the male accessory glands may aid in the identification of p otential semen donors for assisted reproduction programs in captive el ephants.