Cryptorchidism in Goats
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By Cheryl K. Smith I once received a call from a man I had sold two Nigerian Dwarf wethers to nine months earlier, complaining that one of the kids was mounting the other goats and acting like a buck. This was early in my experience raising goats, and I thought I had checked to make sure that both testicles were under the band when he was castrated. Not believing I had made a mistake, I was convinced that the goat must have had three testicles (polyorchidism).
Since then, I have not found any documentation of goats with three testicles, although I know from the literature that, on rare occasions, it has likely occurred in humans, dogs, and cats, so my reasoning was unlikely — but not impossible. The most feasible explanation for the man’s goat was that it was a cryptorchid with only one testicle that could be banded. Such animals used to be referred to as “ridglings.”
What is cryptorchidism?
Cryptorchidism is a failure of one or both testes to descend through the inguinal canal into the scrotum; literally, “condition of hidden testicle.” In humans and some other mammals, the descent of testes can occur after birth, but in goats, it occurs at 12–13 weeks of gestation. If it hasn’t happened by birth, it will never happen.
While the most common presentation is a single undescended testicle — usually the right one in goats (almost 80% in one study of West African Dwarf goats), in some cases, it is bilateral. In cases where both testes are undescended, there is also no scrotum.
Cryptorchidism is known to be hereditary in Angora goats and is assumed to be the main cause in other breeds. The effects of estrogen, androgen inhibitors, and endocrine disrupters during gestation may also cause the condition.
A study in Nigeria of 1,608 bucks found the highest prevalence of cryptorchidism in brown goats and the lowest and black-and-white ones. None of those colored brown-and-black, brown-and-white, and multi-colored had the condition. Body weight was not affected.
How common is it?
The normal prevalence of cryptorchidism is only about 2% but can be much higher if bucks with only one testicle are routinely used for breeding. This is the case in Nigeria, where some owners believe that they are more virile than normal bucks, so prefer to use them for breeding. Such bucks are also believed to put on more weight for market when both testicles have been removed, leading to retention of the cryptorchid bucks for breeding — who then pass the condition on to their male offspring.
In humans and some other mammals, the descent of testes can occur after birth, but in goats, it occurs at 12 to 13 weeks of gestation. If it hasn’t happened by birth, it will never happen.
In one study on West African Dwarf goats in Nigeria, “about 80% of the farmers believed that unilateral cryptorchids are sexually more virile, aggressive, and achieve higher conception rate and annual reproductive turnover than animals with two testicles,” while 10% thought they were the same as bucks with two descended testicles and the other 10% preferred the bucks with two descended testicles.
Another study showed that the outcome of that preference led to 70% of all bucks being cryptorchids. In a study to determine whether the beliefs were true, cryptorchid bucks’ sperm were found to have lower motility (ability to move) and concentration, more abnormalities, and the sperm count was lower. The researchers recommended a campaign to educate goat farmers not to use bucks with this condition for breeding.
What can be done with cryptorchid buck?
Most goat owners do not choose to keep a goat with this defect. A cryptorchid buck doesn’t make a good pet because he will have the behavior of a buck — such as aggression, mounting, and urinating on himself. He will need to be treated like a buck, but steps must be taken to prevent him from breeding the does. In addition, a cryptorchid buck risks developing further problems. An abstract from the Defense Technical Information Center stated that in a study of Angora buck goats, 29.7% of those included had one or more tumors on the hidden testes. This is most likely due to the higher temperature in the abdomen than outside the body.
Surgery to remove the hidden testicle is an option, but it is expensive and requires hospitalization, medication before, during, and after surgery, and either laparoscopic or standard surgery. Laparoscopic surgery is less invasive, less painful, has fewer complications, and a shorter recovery time, but not all vets can do it because of the equipment and expertise required. According to Goat Medicine, sometimes the testicle is found near the kidney, which may further complicate things. Because of this, the testicle may have to be located by ultrasound prior to surgery.
This is where prevention comes in. Smith and Sherman recommend not only that such bucks not be used for breeding but that sires and dams of cryptorchid bucks be culled from the herd and not used for breeding, either.
Conclusion
Goat breeders can expect the random cryptorchid buck from time to time. This is something to check for at birth or shortly after. If the condition is not detected until the animal is castrated, a decision will have to be made about surgical correction, keeping the goat with other bucks and ensuring that breeding does not occur, or culling from the herd.
Cheryl K. Smith has raised mini dairy goats in the Coast Range of Oregon since 1998. She is the owner of karmadillo Press, and author of Raising Goats for Dummies, Goat Health Care, and Goat Midwifery. Her first work of fiction, Shed Boy, a cozy mystery set on a goat farm, is due out in June 2023. www.goathealthcare.com
References:
- Handoo, N, et al. 2020. “Successful laparoscope-assisted orchiectomy in three cryptorchid sheep.” Vet Anim Sci 9: 100112. doi: 10.1016/j.vas.2020.100112.
- Igbokwe, IO, et al. 2009. “Unilateral Cryptorchidism in Nigerian Sahel Bucks.” Int J Morphol 27(3): 805–10.
- Johns, DE, et al. 1968. “Incidence of Cryptorchism and Tumors in the Goat Testes.” https://apps.dtic.mil/sti/citations/AD0668909.
- Oguejiofor, CF, et al. 2018. “Consequences of unilateral cryptorchidism on semen and sperm characteristics in West African Dwarf Goats.” Asian Pac J Reprod 7: 172–77.
- Rutherford, DJ, and E Finding. 2009. “Laparoscopic castration in a cryptorchid pygmy goat.” The Veterinary Record 165(1): 27. doi:10.1136/vetrec.165.1.27.
- Smith, Mary C., and David M. Sherman. 2009. Goat Medicine, 2nd ed. Wiley-Blackwell. P. 617–18.
- Uchendu, CN, et al. 2015. “The influence of natural unilateral cryptorchidism on sperm reserves and haematology of West African Dwarf (WAD) goats.” IOSR Journal of Agriculture and Veterinary Science (IOSR-JAVS) 8(12): 21–28.
