Chapter 59 Diseases of the Urinary System
Primary urinary tract problems are rare in horses because of the pH of the urine, the sterility of the system, and the fact that voiding of the urine serves to wash out any infectious organisms that may be ascending the tract. Urinary tract problems, therefore, are more often secondary to other problems. If a horse does have a urinary tract problem, the following are pertinent questions to ask the owner:
Urinary bladder prolapse is an unusual condition that is most often seen in postpartum mares. Relaxation of the pelvic muscles, dilation of sphincter muscles, and strain during parturition all work together to prolapse the bladder.
Pyelonephritis is a bacterial infection of the kidney and is seen most often in adults. This is usually an ascending infection from lower in the urinary tract. Pyelonephritis is usually a secondary condition to urine pooling/stasis, because urine flow typically washes bacteria down and out of the tract. Bacteria are usually the same as the predisposing cystitis.