B-mode ultrasound in the evaluation of sheep testicles

Abstract

Our objective was to evaluate the testicular integrity of sheep by B-mode ultrasound. We used 16 male sheep of no defined breed, aged from 6 to 36 months weighing from 16 to 71kg, raised in semi-intensive system. Prior to the ultrasound evaluations, the males were weighed and a general inspection and palpation evaluation was performed to detect possible changes in the reproductive system by inspection and palpation. The ultrasound examination was performed fortnightly, obtaining images of each testis, corresponding to the positions: sagittal (longitudinal) and transverse (lateromedial), by a single operator, with the animal in quadrupedal position, without trichotomy, and manual restraint, using an ultrasound. (Honda® - HS1500V) coupled to a 7MHz linear transducer with 8.0 MHz frequency in all evaluations. It was possible to easily identify in the sonographic images the testicular parenchyma, mediastinum and the tunics delimiting the parenchyma. In the central region of the testicular parenchyma, the mediastinum, one line and one point are observed when evaluated in the sagittal and transverse planes respectively and always presented a hyperechoic characteristic in relation to the parenchyma. Testicular tunics, a characteristically hyperechoic structure delimiting the testicular parenchyma, were always observed in the images, visualized as a bright, hyperechogenic line that surrounds the testicular parenchyma separating it from the scrotum. Among the animals submitted to ultrasound examination, three of them one with 16 months of age in reproductive activity and two with 36 months and in sexual rest presented images with points suggestive of testicular calcifications observed until the end of the study. However, several studies did not correlate them with pathologies, and there are controversies regarding their presence when considering the age and composition of the finding. The testicular integrity of sheep can be assessed by B-mode ultrasound. Ultrasound examination of the genital system of sheep may be a useful technique that can be successfully and conveniently used for diagnostic purposes of the sheep testis.