Help! My Goat Can't Pee!

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Caprine Obstructive Urolithiasis

This month, our own Dr. Pelletier is doing a guest spot at Dr. G's corner! Please read her article about urinary obstruction in goats.

   

      Due to a few recent cases of urinary obstruction in pet goats, I would like to provide some information that will hopefully make future and current goat owners more aware of this condition.  Caprine obstructive urolithiasis is the fancy way of saying urinary tract obstruction in a goat.  A urolith is a stone that forms somewhere in the urinary tract, most commonly in the bladder.  Uroliths are formed from minerals in the urine (calcium, phosphorous, magnesium and/or ammonium) when they combine with cells and mucoproteins.  When stones pass into the urethra, they can become stuck and result in either a partial or complete obstruction.  This occurs most commonly in male goats because their urethra is quite long and takes a tortuous path between the bladder and the outside world.  Female goats have a short, straight urethra that allows stones to pass easier.  Early castration in male goats can also predispose them to becoming obstructed because their urethra remains very narrow.

            Several factors can affect the formation of stones.  These include urinary tract infections, pH of the urine, minerals in the diet and the concentration of the urine.  Diet (feed) is one of the most important factors because it can affect mineral content, pH and mucoprotein concentration in the urine.  Concentrated grain rations will increase the likelihood of stone formation due to the promotion of mucoprotein formation and an imbalance of vitamins and minerals.  Grains tend to be too high in phosphorous and magnesium and too low in calcium and vitamin A. 

            So what should you do to prevent obstructions?  If possible (and this is the case with most goats that do not have the demands of breeding, milk production or meat production), do not feed any grain.  Good quality grass hay (Timothy) with the possible addition of alfalfa hay for calcium, is all the feed a pet goat needs for good health.  Some individual goats, however, will need grain to maintain good body condition, so adjust your feeding accordingly.  In addition, a salt block (not mineral) will provide necessary sodium and chloride.  A salt block will also increase thirst and thus water consumption.  Always have fresh, clean water available (do no let it freeze in the winter!).  Adequate hydration keeps the urine dilute and ensures frequent flushing of the bladder so stones won't form.Two pet pygmy goats

            If grain is necessary, feed a small amount and ensure adequate calcium by providing a calcium supplement (alfalfa hay, dicalcium phosphate or calcium carbonate).  Supplements can be provided free choice or in a specific ratio within the diet.  The ratio of calcium to phosphorous in the diet should be 2:1 to 2.5:1.  Adequate vitamin A is also important.  Another preventive measure is adding a urine acidifier to the diet such as ammonium chloride.  Some feeds, such as Blue Seal Lamb Finisher contain ammonium chloride for the purpose of preventing uroliths.

            Since males that were castrated early are at increased risk, delaying castration can aid in preventing stones.  However, they can begin producing sperm quite early so castrating by 3 months of age is recommended.

         Ok, you didn't know and now your goat is blocked, what do you do?  First of all, how do you know?  The first signs to look for are restlessness and anxiety, including tail twitching.  Then the goat may begin vocalizing excessively and straining frequently to urinate.  This looks like the goat is stretching with the hind legs out behind to full length and the back dipped down or arched.  The abdomen may be going in and out.  If the urethra is only partially blocked these signs may be accompanied by a small stream of urine, dribbling or spraying (as with a garden hose you stick your thumb on).  If any urine is being voided it may be bloody and you may see dried crystals attached to hairs surrounding the tip of the penis.  If obstruction goes uncorrected, rupture of the bladder or urethra usually results within 24-48 hours.  Partial obstruction may be present for a much longer time since urine can escape. Whether partial or complete, obstruction warrants immediate attention.

            Once the bladder or urethra ruptures there is an initial decrease in discomfort since the pressure in the bladder or urethra is relieved.  The animal may appear normal again during this period.  However, the subsequent absorption of toxins into the blood from the urine results in weakness, anorexia and depression.  This is fatal if left untreated and death usually occurs within 2-5 days from the initial onset of signs.

            Now, you suspect your goat is blocked and you don't want the bladder to rupture, so what do you do?  Call your veterinarian and have the following information ready: a complete diet history (hay, grain, minerals, other supplements and pasture access), water sources, possible toxic plant ingestion, previous health information, medications, age at castration, duration of problem, description of problem and progression of signs.Male Goat Anatomy

            This history will help us confirm that it is indeed an obstruction.  In addition to this we will perform a physical examination, including palpating the bladder and examining the penis (usually with sedation).  The penis will be exteriorized (often a frustrating and time consuming task in itself) and examined.  One of the most common places for a blockage is right at the tip of the penis, in the urethral process. If this is the case, the obstruction may be squeezed out with the fingers or the tip may simply be cut off.  In either case, if obstruction has occurred in the urethral process, it should be removed to prevent future blockages. If the blockage is deeper than the penis, a catheter will have to be passed into the urethra to try to dislodge it.  With the catheter, sterile saline is flushed in to dilate the urethra and hopefully loosen the obstructing object.  Unfortunately passing a catheter is not always successful and is often traumatic.  Medications such as non-steroidal anti-inflammatory medications and antibiotics are sometimes tried but have variable results.

            If the goat is successfully unblocked and urine is obtained, a urinalysis should be performed.  This evaluates the urine for crystals, inappropriate pH and signs of infection.  Any abnormalities should be addressed.  Medical treatment may include antibiotics, anti-inflammatory medications, adjusting the diet to reduce minerals and mucoproteins, or adjusting the pH with urinary acidifiers.  If the obstruction is adequately relieved than these adjustments may be enough to prevent recurrence.  However, in most cases the first obstruction is not the last, owing to an accumulation of stones in the bladder that will continue to be flushed into the urethra.  Other diagnostics to evaluate for stones are recommended.  This may include radiographs (x-rays) or an abdominal ultrasound.    

       Evidence of stones in the bladder, recurrence of obstruction or inability to relieve an obstruction medically (with a catheter, flushing and medications) is indication for surgery or euthanasia.  Several surgical techniques are available; however, the prognosis with all of them is guarded to poor for a long term outcome. 

            The main take home point is that no medical or surgical option is as effective as prevention through proper management of your goats.  By following a few simple guidelines, hopefully, your goats will remain blockage free for the duration of their lives. If you have pet goats or are interested in getting goats as pets, please feel free to contact us to discuss routine and preventative care.

- Beth A. Pelletier, DVM