Ultrasound for the diagnosis of cryptorchidism
Keywords: stallion, equine, cryptorchid, diagnosis, ultrasound
Image size: 1311 x 1983px
The intra-abdominal testicle in this 7 year old Quarter horse stallion were not easy to palpate per rectum but this image was captured using a 5 MHz intra-rectal transducer using and random scanning in the area of the right internal inguinal opening. As is often the case, this intra-abdominal testicle could not be seen by trans transabdominal scanning in the inguinal region.
Although ultrasound images are best analyzed using video capture, this still image illustrates the testicular echo and its homogeneity fairly well. Note that the size of this testicle is considerably smaller than normal if one considers that the diameter of a transverse section of a normal testicle is about 5 to 6 cm. In this case it is about 3.5 cm.
Note: Although spermatogenesis is suppressed completely in cryptorchid testicles, the function of the Leydig cells is only slightly compromised and steroidogenesis remains close to normal. This is why the hCG stimulation test (Cox test, measuring paired testosterone concentrations) and estrone sulphate test are useful for diagnosing cryptorchidism.
