Blood in Cat Urine

In some cases, hematuria can be caused by something minor like a urinary tract infection; however, other times it can be associated with more serious conditions such as bladder stones or a life-threatening urinary obstruction. A visit to the vet is in order if you see blood in your cat’s urine, but let’s explore what pet parents should know and watch for at home. 

What is Hematuria (Blood in the Urine) in Cats?

Hematuria is a term referring to the presence of red blood cells in the urine. This may be at the microscopic level, or you may see a pink or red color in your cat’s urine. 

How To Tell if Your Cat Has Hematuria? Other Clinical Signs

Identifying bloody urine isn’t always as obvious as you would think, especially if your cat is peeing in the litter box. However, you may notice some of the following clinical signs depending on the severity and underlying cause. 

• Pink or red color to the urine
• Urinating outside of the litter box
• Urinating small amounts frequently 
• Increased thirst and urination 
• Straining to urinate
• Inability to urinate (this is a medical emergency) 
• Vocalizing in the litter box 
• Pain
• Excessive licking of the lower abdomen or genitals  
• Rarely systemic signs (decreased appetite, lethargy), bleeding from other areas of the body (mouth, nose, rectum), or bruises/small dots on the skin 

What Causes Blood in Cat Urine?

Urinary Tract Infection

Urinary tract infections are most often caused by bacteria in the bladder or urinary tract. While it is always important to check for the presence of a UTI in a cat who is peeing blood, it is actually not a very common cause. Urinary tract infections can be diagnosed based on urinalysis and urine culture, and are treated with antibiotics. 

Stones

Bladder stones are hard mineral deposits that can form in the urine. They may be smaller than a grain of sand or much larger. There are several different types of stones that can form, the most common in cats being struvite stones. Bladder stones are generally diagnosed with urinalysis, X-rays, and ultrasound. 

Depending on the type of stone present, it may or may not show up on X-rays. Treatment also depends on the type of stone present. Some can be dissolved with a prescription diet, while others require surgical removal. In some cases, a stone or part of a stone may block the flow of urine, which is a medical emergency. 

Feline Idiopathic Cystitis 

This is the most common cause of hematuria in cats, yet in some cases can be complex to diagnose and treat. Feline idiopathic cystitis (FIC) has many names, including Pandora Syndrome, and refers to inflammation of the bladder. The clinical signs wax and wane in response to stress. FIC is diagnosed when all other conditions causing lower urinary signs (such as UTI, stones, etc.) have been ruled out. Treatment most frequently involves environmental changes to control stress, diet change, increased hydration, and pain medication. 

As stress has a huge impact on FIC, decreasing stressors for your cat will be a major part of treatment and prevention. This includes things like: 

• Proper litter box hygiene – having an appropriate number of litter boxes in safe locations, a substrate that your cat approves of, and keeping the boxes clean. 
• Making sure that your cat has access to key resources, including food, water, rest areas, litter boxes, scratching post, and toys.
• Provide enrichment for your cat by letting them use their natural hunting instincts through play and feeding toys. 
• Consider Feliway, other calming supplements, or anti-anxiety medications.  

See the Indoor Pet Initiative for additional tips on stress reduction and enrichment for your cat. 

Obstruction

Urinary obstruction is a medical emergency in which the urethra becomes blocked by stones or urethral plugs, preventing urine from exiting the bladder. It is most common in neutered male cats. Straining in the litter box and frequent attempts to urinate are the most common clinical signs; however as the condition progresses, the cat will become severely ill due to an electrolyte imbalance. In addition to history and physical exam (in which a large hard bladder can be felt in the abdomen), bloodwork, x-rays or ultrasound, and urine culture may also be recommended. 

Treatment involves immediate hospitalization so that your vet can pass a catheter into the bladder and drain the urine, fluid therapy, and medication. The catheter will need to remain in place for several days while your cat recovers. Your vet will discuss diet change and stress management to help prevent another blockage from occurring in the future. Cats who have had multiple urinary obstructions or are unable to be unblocked with a catheter may need surgery known as a perineal urethrostomy.

Cancer

Tumors in the urinary tract, kidneys, or bladder are another possible cause of hematuria. In addition to bloody urine, cancer can cause abdominal pain, weight loss, and lethargy. Tumors may be diagnosed on x-rays, ultrasound, bloodwork, and urinalysis to assess kidney function, and biopsy or sampling of the mass. While some tumors are benign, others have the potential to spread to other parts of the body. Treatment will depend on the type and location of the tumor and may include medical management or surgery. 

Trauma

Injury to the abdomen or urinary tract can be assessed on physical exam and imaging. Treatment will vary depending on the cause and extent of the trauma. 

Bleeding Disorder 

Conditions affecting the ability of blood to clot properly can lead to bleeding from several areas of the body, including into the urine. Specific blood tests can help diagnose these conditions. 

Other 

Other conditions, such as kidney disease or congenital abnormalities, can also lead to hematuria. 

Diagnosing Hematuria

If your cat is peeing blood, it will require a thorough veterinary exam and diagnostics to determine the underlying cause and appropriate treatment. 

• Urinalysis – to evaluate the urine’s physical, chemical, and microscopic properties, including whether blood, crystals, or bacteria are present 
• Urine culture – to identify the presence of infection and determine the most effective antibiotics 
• Bloodwork – to evaluate your cat’s overall health as well as their kidney function 
• X-rays – to help visualize some types of bladder stones or other abnormalities 
• Ultrasound – to help visualize the soft tissue structures of the urinary tract, bladder stones, tumors, or other abnormalities

Remember that feline idiopathic cystitis, the most common cause of hematuria in cats, is a diagnosis of exclusion. Your vet will likely recommend many of the diagnostic tests listed above to rule out other possible causes for your cat’s bloody urine. 

Blood in Cat Urine Treatment

The treatment for hematuria will depend on the underlying cause. In addition to treatments performed or prescribed by your vet, you will likely have to make changes to your cat’s environment or diet. Some possible treatments may include:

• Antibiotics for urinary tract infections
• A dietary change for bladder stones or FIC
• Medications and stress management for FIC
• Surgical intervention for obstructions, tumors, bladder stones, or severe trauma 
• Additional supportive care, such as pain relief and fluid therapy

Some causes of blood in cat urine may fully resolve with treatment, however, others may be more difficult to treat or are likely to recur in the future.