Signs & Symptoms of a Urinary Tract Infection in a Horse

By Jane Meggitt

Horses don't often suffer from urinary tract infections, but they can happen. Urinary tract infections involve the kidneys, bladder, ureters -- the tubes connecting the kidneys to the bladder -- and the urethra. While you probably see your horse passing manure regularly, you might not catch him urinating quite as often. Still, if you know he generally urinates at a particular time and in a particular place -- perhaps when he goes back to his stall after turnout -- watch him "go" to catch any symptoms as soon as possible. Call your vet if you notice any changes in your horse's urinary habits. If possible, collect a urine sample to bring to your vet for testing.

Urinary Tract Infection Symptoms

Symptoms of an equine urinary tract infection include:

  • Pain while urinating
  • Difficulty urinating
  • Passing small amounts of urine
  • Frequent urination
  • Blood in the urine
  • Pus in the urine
  • Cloudy urine
  • Clots or particles in the urine.

If your mare is in season, it's normal for her to dribble small amounts of urine and is not indicative of an infection.

Equine Cystitis

Cystitis, or bladder inflammation, more often affects mares but geldings and stallions can develop it. Usually the result of a bacterial infection, your vet diagnoses the condition by performing blood tests and a urinalysis. She also may conduct an endoscopy on your horse, inserting a thin tube with a camera on the end into the urethra on to the bladder, where she can view the bladder's interior. Your vet might use a catheter to take a sample of bladder fluid and sediment. Treatment generally consists of antibiotics and pain medication, but horses prone to cystitis may suffer repeated occurrences.

Kidney Infection

Equine kidney infections come in two basic forms. The first, formally known as pyelonephritis, generally begins as a urinary tract infection that travels to the bladder and on to the kidneys. Kidney stones or stones in the ureter can cause kidney infections. Symptoms include:

  • Fever
  • Weight loss
  • General malaise
  • Pain in the area of the kidneys
  • Constant thirst and frequent urination.

In addition to blood and urine testing, your vet may conduct X-rays or ultrasounds. Treatment consists of aggressive antibiotic therapy and possibly intravenous fluid therapy. In a worst-case scenario, the horse requires surgical removal of the affected kidney.

The other type of kidney infection, interstitial nephritis, result from bacterial infection spread from other areas of the body. Kidney failure can occur. Treatment includes antibiotics and intravenous fluid therapy.

Sheath Infection

If your gelding or stallion's sheath becomes infected, he may display some of the symptoms of a urinary tract infection along with other signs. These include:

  • A foul or discharge odor emanating from the penis
  • Sheath swelling
  • Leaving the penis out rather than withdrawing it into the sheath
  • Kicking at his abdomen.

Sheath infections are often secondary infections from bug bites or open sores. "Summer sores," or infestation with fly larvae, also can result in infection. Your vet probably will need to sedate your horse to inspect the sheath. Treatment may include antiseptic cleaning of the sheath and antibiotic administration.