What Causes Blood in Pet's Urine?

One of the most common medical complaints in the small animal veterinary clinic is the history of bloody urination in our pets. Bloody urination can have many causes in pets, and occurs in both dogs and cats. Probably the most likely cause in most cases is the presence of a urinary tract infection. Pets may develop urinary tract infections for many reasons, including stress, immune deficiencies, anatomic defects, or the presence of another metabolic disease including kidney disease or diabetes. Pets with urinary tract stones are also prone to developing secondary bacterial infections of the urinary tract.

Symptoms of a urinary tract infection:

Symptoms of a urinary infection may include:

  • Inappropriate urination in the house or outside of the litter boxes
  • Bloody urination
  • Increased urgency and frequency of urination
  • Straining and producing little urine.  

Since these symptoms may mimic urinary tract stones, and even urinary tract blockages in some cases, it is important to have a full veterinary workup and evaluation should a pet have a history of bloody urination and/or these other symptoms. Many pets with urinary tract infections will also often develop crystals or mucous plugs in the urinary tract which can create even more problems for the patient. When this occurs in especially male cats, life threatening obstructions of the urinary tract may occur, stressing the importance of prompt veterinary attention in all of these patients. Dietary factors play a role in some cases of urinary infections and crystals, and veterinarians may change the diets of affected patients, based on a microscopic urine analysis.  

Other causes of bloody urination in pets include polyps in the urinary tract or even tumors, especially in older pets.  Trauma of the urinary tract can also result in bloody urination. Finally, pets with other metabolic disorders, including clotting deficiencies (seen in liver disease, rodenticide exposure, and platelet disorders) also may present with bloody urination.

Remedies for dogs and cats with bloody urine

Treatment of blood in pet's urine will depend upon the underlying causes outlined above.  If a urinary tract infection is diagnosed, appropriate antibiotic therapy usually for a minimum of 2 to 3 weeks is often needed. Depending upon the type of infection, sometimes additional supportive supplements, including vitamin C and cranberry products can be helpful in some cases. Feline and canine renal support by the company Standard Process are also excellent whole food supplements. If stones are diagnosed, then both medical and dietary therapy to dissolve the stones or surgery is often needed to remove them. Cats with chronic bloody urination (known as feline urologic syndrome or FUS) will often need a multifaceted approach to treatment, including antibiotics, dietary therapy and nutritional supplements.  

In other cases with chronic bloody urination, further testing, including urine cultures and ultrasound may be needed to rule out other diseases such as hidden stones, polyps or bladder tumors. If a medical workup reveals other diseases or clotting problems, then addressing these underlying diseases will often result in resolution of the bloody urination.  Prognosis for cure of blood in a pet's urine is usually excellent with a thorough veterinary workup to define the specific cause(s).