Urinary calculi, or kidney or bladder stones, are common terms used to identify the condition known as obstructive urolithiasis. In goats, clinical obstructive urolithiasis is most frequently seen in young, castrated males with the calculi comprised of phosphate salts. A calculi is a hard mass of mineral salts in the urinary tract. Goats fed excessive grain are at increased risk. This condition leads to the inability to void urine normally because of obstruction of the urinary outflow by the calculi. When the urethra becomes blocked forceful attempts to urinate will produce little or no voided urine. Animals will then experience renal failure and toxemia. Unless the obstruction is relieved, spontaneously or by intervention, the urinary bladder or the urethra will eventually rupture.
Symptoms: Symptoms include restlessness, and anxiety. Tail twitching is also an early sign. Affected animals will be extremely vocal, with frequent straining. Often this straining is misinterpreted as straining to pass manure. Drops of blood may be present in the urine or crystals may be evident on the hairs around the prepuce. Animals with partial obstruction may be able to void small intermittent streams of urine but will show discomfort.
Treatment: This condition in most cases will require the assistance of a veterinarian. The calculi will have to be dislodged or removed. Without preventative management this is likely to be a recurring problem for an individual. Also, it is important to recognize that the disease may be brewing in multiple animals in the herd kept under the same conditions.
Prevention: Control consists of dietary management. The calcium to phosphorus ratio should be in the range of 2:1 to 2.5:1. Alfalfa hay with heavy supplementation of grain concentrate is a major predisposing factor. Diet high in grass should be stressed. Reduce grain intake and add calcium supplements such as dicalcium phosphate and calcium carbonate, made available free choice or mixed into the feed to adjust calcium to phosphorus ratio. Other measures include adequate amounts of clean, fresh water, especially in the winter, and access to free-choice salt. The addition of urinary acidifiers, like ammonium chloride, to the ration may be useful in preventing crystal formation.
Reference: Mary C. Smith & David M. Sherman: Goat Medicine.
