Urolithiasis in Goats
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While springtime goat care often focuses on does and kidding, don’t forget the male goats in your herd. Serious health issues can result from lumping their care in with late gestation does. Male goats, particularly those with high concentrate — or grain — diets, are at increased risk of developing bladder stones. Bladder stones, medically known as uroliths, can lodge in a male goat’s urethra and prevent urination, this is urolithiasis, and this condition can be life-threatening.
Uroliths can form as precipitates in the urinary bladder of both male and female goats. Male goats, however, risk those stones becoming stuck and obstructing the exit because of their long, narrow urethra (the tube that connects the bladder to the outside world). Several types of stones can form in the bladder — phosphatic, silicate, calcium oxalate, and calcium carbonate.
Phosphatic stones are the result of animals eating diets that are high in phosphate. These diets are generally high in concentrate. Animals eating pelleted feeds, even hays, also have an increased risk of forming these stones. Silica uroliths result from animals consuming grasses that are high in silica. These grasses are native to western North America. Animals grazing these grasses are at particularly high risk if there is limited access to water. Calcium oxalate and calcium carbonate crystals form when males consume feeds high in calcium. These can include alfalfa hay or lush clover pastures.
Male goats that have developed an obstruction can have varying clinical signs. They can be depressed and off of feed or be vocalizing, stretching, and even posturing to urinate. Owners may observe some mild bloat. If unable to urinate for 12-24 hours, the pressure of urine build-up can rupture the bladder or even the urethra. Once the bladder has ruptured, animals will temporarily become significantly more comfortable as the pressure has reduced.
Obstruction is diagnosed after careful examination of the animal. Male goats exhibiting any signs indicative of possible obstruction should be monitored carefully for their ability to urinate. Pygmy goats should be especially considered at risk, as their small urethral size makes them more likely to have obstructions. Palpation of the bladder and abdominal ultrasound can help identify the obstruction.
Treatment for obstructive urolithiasis depends on the location of the obstruction, the time of diagnosis (rapid or after bladder or urethral rupture), and the purpose of the animal. Goats with obstruction often have compounding conditions, such as dehydration. These conditions are addressed before pursuing treatment of the stones themselves. Goats are also treated with pain management and sedation.
Male goats have a small urethral process at the end of their penis. Sometimes, this is the location of the obstruction. Every animal should undergo an examination and removal of this process. Removal of the urethral process does not affect fertility or function. If the obstruction is further up the urethra toward the bladder, veterinarians can pursue a variety of surgical treatments. The procedure chosen depends on the goat’s future job and the current state of the obstruction. Goats that have already ruptured their bladder or prepuce before treatment have a worse chance of recovery.
As one would guess, treatment of urethral obstruction in male goats is expensive and often unrewarding. Prevention of this serious condition is much simpler than pursuing treatment. The prevention of urolith formation primarily aims to control mineral consumption in the diet and increase water intake.
Ensuring a balanced mineral ration can greatly reduce the risk of stone formation. Goats on high concentrate diets should have their diet carefully monitored to ensure that the ratio of calcium to phosphorus is appropriate. If you are not feeding a complete goat feed, it is highly recommended that you consult your veterinarian or an animal nutritionist to ensure that the diet is appropriate. Further, in animals that do not require supplementation with grain, such as healthy pets or breeding animals in the off-season, it is recommended to avoid feeding concentrates. Healthy animals can meet most of their dietary needs by quality hay and loose or block mineral supplements.
Ensuring appropriate water consumption can be as easy as providing a clean and easily accessible water source. In cold weather or range situations, this can be more difficult. It is imperative to check your water supply daily to ensure that animals have access and clean water. Providing supplementation with salt can also further encourage water intake, and salt can be provided free-choice or sprayed on feed.
In animals with an increased risk of stone formation, the feed additive ammonium chloride can also reduce the risk of stone formation. It adjusts the acidity of the urine to make stone formation more difficult.
Some discussion has been made about the timing of castration causing an increased risk of stone formation in those males. Early castration does result in decreased diameter of the urethra. In male goats intended to be kept as pets, delaying castration can result in a larger urethra and reduce the risk of obstruction. This should not be used as a primary method of prevention, however.
Obstruction of the urethra by uroliths is a serious condition in male goats. Make a thorough health management plan for the male goats in your herd to reduce the risk of stone formation. Utilize your herd veterinarian or a nutritionist if you have feedstuffs or pastures that may increase the risk of urolith formation. If you are concerned that your male goat may be exhibiting signs of obstruction, it is imperative to contact your veterinarian immediately. Rapid diagnosis and treatment can significantly improve the chances of recovery.
David C. Van Metre, DVM, DACVIM. Urolithiasis in Small Ruminants: Surgical and Dietary Management. Colorado State University. http://www.aasrp.org/resources/VanMetre_urolith_surgery_04.pdf
David C. Van Metre, DVM, DACVIM. Prevention of Urolithiasis in Livestock. Veterinary Extension, Colorado State University. http://veterinaryextension.colostate.edu/menu2/sm%20rum/Urolithiasis%20prevention.pdf
Meredith Jones, DVM, MS, DACVM. Urolithiasis in Ruminants. Oklahoma State University. Modified March 2021. https://www.merckvetmanual.com/urinary-system/noninfectious-diseases-of-the-urinary-system-in-large-animals/urolithiasis-in-ruminants
Originally published in March/April 2022 Goat Journal and regularly vetted for accuracy.