Effects of LHRH-analogue treatment of spermatogenic dysfunction in the dog

Summary Three male dogs, aged 2–4 years, which exhibited a high percentage of sperm with abnormal tails in their semen and low levels of peripheral plasma LH and testosterone were given two injections of 400 μg an LHRH analogue (LHRH‐A) 3 h apart. The semen quality of all three dogs and the peripheral plasma levels of LH and testosterone were examined in two of the dogs. Plasma levels of LH and testosterone in both dogs peaked at 30 and 90 min respectively, after the injection of LHRH‐A. The semen quality of all three dogs had improved temporarily 20 days after the injection. To be specific, although the mean percentage of sperm with abnormal tails in the three dogs was 19, 26 and 32% respectively before injection of LHRH‐A, these values had decreased to 10, 16 and 13%, respectively, 20–40 days later. Thereafter, however, the percentage sperm abnormalities increased again. The testes and epididymides of two of the dogs were examined histologically at the end of 90 days. Sloughed germ cells were observed in the seminiferous tubules of the testes, and pyknotic epithelial cells were noted in some of the epididymal ducts. The other dog, which had a history of three unsuccessful matings was treated again with LHRH‐A and mated with three bitches 30, 75, and 110 days later, respectively. Only the bitch mated with this dog 30 days after a second series of injections conceived. It is assumed that the semen quality of the three dogs improved because of a temporary rise in plasma LH and testosterone levels after the injection of LHRH‐A. It is concluded that the fertility of dogs with a high percentage of sperm with abnormal tails can be improved approximately 30 days after treatment with an LHRH‐A.