VSR 421: Regional Veterinary Surgery (2+1)

CONDITIONS AFFECTING THE TESTIS

Congenital conditions

• In the fetus, the testes are located intra-abdominally near the kidneys. They descend into the scrotum in cats and dogs by about five days after birth. However, normal testicular descend may take six months to complete in some animals.
• Failure of the embryonic development of the testicles or their descent into the scrotum can result in congenital abnormalities like anorchism, monorchism, testicular hypoplasia or cryptorchidism.
• Anorchism is the congenital absence of both testicles. It is rare in companion animals. Monorchism is the congenital absence of one testicle, the left testicle being usually absent.
• Anorchism and monorchism can be diagnosed by careful palpation of the scrotum, inguinal region and the abdomen (intra-abdominal testes are usually palpable only when they are larger than normal). Ultrasonography, laparoscopy or exploratory laparotomy may be required for confirmation.

Testicular tumour

• The conditions are usually asymptomatic except for the failure of development of secondary sexual characters in cases of anorchism and need not be treated.
• Testicular hypoplasia may affect one or both testicles. The affected testicles may be located within the scrotum, will be very small, normal or soft in consistency and difficult to palpate.
• Usually animals which are bilaterally affected will be sterile. However, the testicular hormones may be produced. Some of the affected animals may show feminization and orchiectomy may have to be performed.
• Cryptorchidism is the failure of one or both testicles to descent into the scrotum from the abdominal cavity.
• This is the most common congenital condition affecting the testes. Unilateral cryptorchidism is more common and the right testicle is mostly affected.
• The ectopic testis/testes may be located in the prescrotal region, inguinal canal or within the abdominal cavity, the latter being more common. The condition may be diagnosed by careful palpation of the prescrotal region, inguinal canal and the abdominal cavity (normal sized intra-abdominal testicles are difficult to palpate). Ultrasonography, laparoscopy and exploratory laparotomy may be required for the diagnosis of intra-abdominal cases of cryptorchidism.
• In bilateral cases of cryptorchidism the animal will be sterile as the germinal cells of the testes undergo degeneration in the raised ambient temperature in the ectopic location. However, the endocrine function remains normal and even in cases of bilateral involvement the secondary sexual characters are normal. But, feminization may be seen in cases where the ectopic testicle/testicles have developed Sertoli cell tumour as intra-abdominal ectopic testicles have a high tendency to develop neoplasms especially Sertoli cell tumour and seminoma. The intra-abdominal ectopic testicles also are prone to suffer from torsion as they are more freely movable.
• Treatment involves orchiectomy. Bilateral orchiectomy is preferred even in unilateral involvement to prevent the onward transmission of genes responsible for the condition. The pre-scrotal or inguinal testes are removed through an incision placed on the skin directly over the ectopic testicle. Intra-abdominal testicles are removed through a ventral median laparotomy incision.