Twenty four adult clinically healthy one-humped male camels (Camelus dromedarius) were examined three times (beginning, mid and end) in each season (winter, spring, summer and autumn) for establishing the normal ultrasonic appearance and seasonal changes in the testicular parenchyma in the natural ecology of Punjab, Pakistan. The testes of each camel were scanned by using a B-mode real time ultrasound scanner fitted with a 7.5-MHz linear-array transducer. Scrotal biometry was done with the measuring tape during all the seasons of year. The tunics of the testes appeared as hyperechoic lines surrounding the homogenous, moderately echogenic parenchyma of the testis. The mediastinum testis was visualized as hyperechoic central line and a spot, in longitudinal and transverse sections, respectively. During winter season, the parenchyma was hyperechoic and mediastinum testis was seen as thin hyperechoic line. In spring, the echogenicity of parenchyma was moderate and mediastinum appeared relatively thick central hyperechoic line. In summer and autumn, less echoic parenchyma and thick band of mediastinum was recorded. Biometric studies showed significantly (P<0.01) higher scrotal length and width of the testis during winter and spring season as compared to summer and autumn. Present study revealed that the ultrasonic structure of camel testis resembles other mammals and season has an apparent effect on the testicular size and echogenicity of the testicular parenchyma in the one-humped camel.

Key words: One-humped camel, Epididymis, Season, Testis, Ultrasound imaging