Ultrasonography of spontaneous lesions of the genital system of three rams, and their influence on semen quality

Three young Suffolk ram lambs had lesions which rendered them reproductivel y unsound. One had a unilateral scrotal hernia, detected by palpation, and two had sperm granulomas which were detected by trans-scrotal ultrasonograp hy at 18 to 20 weeks of age, before they could be detected by palpation. Ch anges in the lesions were monitored ultrasonographically at two-week interv als with a 7.5 MHz linear array transducer. On the day of each examination, semen was collected from the rams with sperm granulomas by using an artifi cial vagina, and their libido was assessed. Semen could rarely be collected from the third ram. Comparisons were made with similar data obtained from two normal rams. When the rams were 20 to 21 months of age, they were vasec tomised on the normal side, so that the influence of the lesions on semen c omposition and libido could be assessed, and semen was collected and evalua ted until they were euthanased at approximately 24 months of age, when the genital system was examined for gross lesions. The sperm granulomas changed in size (one of them increased in size by about 30 times) and echotexture over the 19-month period of the study, whereas the scrotal hernia, which co ntained omental fat, remained fairly constant. The libido of the two rams w ith sperm granulomas was comparable with the two normal controls. The total mean (sem) number of sperm in the ejaculates were 1.11 (0.10) x 10(9) and 2.03 (0.17) x 10(9) sperm/ml in the affected rams and 4.11 x 10(9) sperm/ml in the normal rams over the same period; the differences were significant (P < 0.05). After unilateral vasectomy, the ejaculates from these two rams contained small numbers of dead spermatozoa, mostly with degenerate heads. Postmortem examination confirmed the gross lesions identified ultrasonograp hically.