Cryptorchidism in the dog: occurrence of cryptorchidism and semen quality in the cryptorchid dog.

Abstract

Occurrence of cryptorchidism in the mongrel dogs was examined at the Tokyo Metropolitan Government Animal Pound and the dogs suspected to be cryptorchidism were transported to our laboratory. Then sexual behavior to estrous bitch was checked and ejaculatory function by digital manipulation and the collected semen quality were examined. In 2, 356 mongrel dogs examined, cryptorchidism was found in 29 cases (1.2%), and all of them were unilateral cryptorchidism. Among the 29 cases, 21 were inguinal cryptorchidism and the remaining 8 were abdominal. Occurrence of cryptorchidism was not different between right and left. Libido of the dog was generally feeble and in 8 of 19 cryptorchid dogs in which ejaculatory function was checked, ejaculation could not be seen. In the cryptorchid dogs semen volume and total number of spermatozoa were few (7.2 ml and 1.2×108 per ejaculate on the average respectively), sperm motility was low, and abnormal sperm and immature sperm rate were high (20.2% and 19.4% respectively), as compared with semen qualities in normal dog.