Cryptorchidism in Cats
Cryptorchidism is a condition characterized by incomplete or nonexistent descent of the testes. The testes normally descend into the scrotum while an animal is still very young. For cats, the testes have generally dropped into place before birth. When the descent of one, or both, of the testes does not take place, the testis that has not descended is retained somewhere in the lower part of the body. For example, they are sometimes retained in the inguinal canal - a passage in the groin that conveys the spermatic cord to the testes. If the testis is in the inguinal canal, it can be felt (palpated) during a physical examination. If the testis is deeper in the abdomen, it will be difficult to palpate or identify with an X-ray. Ultrasound is the best available option to determine the size and location of the testis if it is in the abdomen.
This abnormality can occur in almost all breeds, with the right and left testes failing to descend at equal frequency (neither testis is more likely than the other to be retained). One-sided failure to descend is more common than both sides failing to descend. Ranges of 1 to 1.7 percent of cases have been reported in the cat population. The condition may be inherited, but there is no data that documents a hereditary defect in cats. The surveys that have been conducted regarding cats have over-represented Persian cats and underrepresented other breed populations, making any findings for this condition inconclusive.
Symptoms and Types
This condition is rarely associated with pain or any other sign of disease. However, acute onset of abdominal pain generally indicates that the spermatic cord of the retained testes has become twisted, cutting off the blood supply to the testis. Many times, this testis will develop tumors, which is symptomized by feminine behavior.
What causes the testis to remain undescended, or incompletely descended, is unknown. Some of the reasons that have been concluded so far have pointed to a genetic flaw. Conversely, the condition may not have a hereditary predisposing factor at all, but may still be linked to an occurrence that took place in the intrauterine environment during the formation of the developing fetus (i.e., pregnancy). An adverse condition or environmental factor can lead to a congenital malformation, perhaps affecting only one in a litter. This condition is not preventable.
To arrive at a diagnosis, your veterinarian will use ultrasound to locate the undescended testis if it is suspected to be in the abdomen, along with palpation (touch) of the groin and abdomen to locate the testis. Although rare, a cat may have both testes undescended. There will be an attendant odor of urine about the cat that is indicative of this condition.
The castration of both testes is generally recommended. Even if one testis has descended and the other has not, your veterinarian will most likely counsel you to have both removed. Surgical placement of an undescended testicle into the scrotum is considered unethical.