Urinary Tract Obstruction in Dogs

A urinary tract obstruction is typically caused by stones in the urethra. A partial or full blockage results in difficulty urinating, which may lead to dangerously high levels of potassium and other conditions. This is more common in male dogs, though it may occur in female dogs as well. All cases of obstruction need to be treated by a veterinarian as soon as possible to reestablish urine flow.

When a stone forms or is carried into the urinary tract, it may block the flow of urine. If your dog is straining to urinate, see a veterinarian immediately, as a full blockage is a serious condition that needs to be treated right away to prevent permanent damage or death.

If your dog is suffering from a urinary tract obstruction, he or she may exhibit a range of symptoms, including:

• Difficulty urinating
• More frequent bathroom trips
• Bloody urine
• Loss of appetite
• Lethargy
• Vomiting
• Pain

Your dog may be more prone to accidents in the house, and when he or she does urinate, the amount will be small and appear as a thin stream.

A urinary tract obstruction is typically caused by a stone lodging in the urethra, narrowing the tube through which urine passes. These stones may either form in the urinary tract or be carried out from the bladder. Tumors, inflammation, and disease of the prostate gland may also result in an obstruction in the urinary tract.

Though these obstructions can occur in both male and female dogs, it is more prevalent in the former and result in more severe illness due to the males’ long, narrow urethras. Any stone that passes through has a higher likelihood of lodging and creating a full obstruction.

If you notice your dog straining to urinate, or if you find blood in your dog’s urine, visit the veterinarian immediately. The veterinarian will palpate your dog’s bladder and urethra and perform a rectal examination, which may reveal stones in the bladder or urinary tract or an enlarged prostate in male dogs. Other diagnostic tests that may help identify the obstruction include:

• Urinalysis
• Urine culture
• Blood test
• X-rays
• Ultrasound
• Biopsy of tissue from the urinary tract

Imaging can help discover suspicious masses, such as bladder stones or tumors, while blood work and urinalysis test electrolyte and kidney values and reveal bacteria or crystals. By performing a variety of tests, your veterinarian can both discover the source of the obstruction and establish the extent of the damage to other areas. An inability to urinate may lead to infection, elevated potassium levels, and kidney damage, all of which will need to be addressed as part of your dog’s treatment.

Depending on the extent of the blockage, your dog may need to be hospitalized until urine flow has been reestablished. This is typically accomplished by inserting a catheter into the urethra to drain urine and by flushing the stones back into the bladder. If the obstruction cannot be removed with this method, surgery may be required.

The urinary tract obstruction itself is not a disease but rather a symptom of another condition, such as bladder stones or cancer, which will need to be addressed to prevent future blockage.

Medical Management

Once the stone has been flushed into the bladder, it can be dissolved through a combination of drugs and a prescription diet. Certain foods may soften the stone enough for it to pass through the urethra successfully. Fluid therapy prevents your dog from becoming dehydrated while moving waste and toxins out of the bloodstream more quickly.

Surgical Treatment

For male dogs with an enlarged prostate, castration is standard in order to reduce the prostate’s size. Surgery may also be necessary to remove the stones from the bladder or urethra if they cannot be broken up by ultrasonic waves or dissolved by less invasive means.

Once the obstruction has been removed and your dog is able to pass urine normally again, you must ensure that your dog is receiving enough fluids in order to flush out accumulated waste. Monitor your dog’s urination frequency and amount, and check for blood in the urine. Administer any prescribed medication according to your veterinarian’s instructions, and provide your dog with easy access to clean, fresh water.

If your dog underwent surgery as part of the treatment process, you will need to restrict physical activity and enforce plenty of rest until the surgical site has healed. You may need to bring your dog back to your veterinarian for follow-up exams to ensure that the stone has dissolved and that the obstruction has not returned.