A frequent reason a cat is brought to see me is blood-tinged urine. Often bloody cat urine is accompanied by my patient urinating outside the litter box. This behavior usually makes the problem easier for pet parents to identify, but it's not the only sign of a possible urinary issue.
What Color Is Cat Pee?
In healthy animals, cat urine is yellow. Cat urine can be pale in color or appear more amber, but it should look clear, not cloudy. If you notice cat urine that is cloudy or tinted orange or red, it could be hematuria (blood in the urine).
What is Hematuria (Blood in the Urine)?
If you notice changes to the color of your cat's urine, it could be from hematuria (the medical term for blood in urine). Sometimes, hematuria is easy to see. For example, your cat's urine may appear darker or reddish. However, sometimes there's such a small amount of blood in the urine your vet needs to examine a sample under a microscope to be sure.
Signs of Hematuria in Cats
Pet owners often discover blood in cat urine when they notice other unusual bathroom habits in their feline friend, such as:
- Peeing outside their litter box
- Peeing more or less often than usual
- Changes in the amount of urine
- Meowing while peeing
- Changes to the smell and color of the urine
- Increased licking or cleaning around the genitals
What Causes Bloody Urine in Cats?
There are three common reasons for bloody urine: urinary tract infections, crystals in the urine, and interstitial cystitis. A urine sample may be needed to determine the specific cause.
Urinary Tract Infections
A urinary tract infection (UTI) is an infection in a cat's (or human's) bladder, kidney, urethra, or ureter (the connecting tubes between the kidneys and the bladder). The infection can be limited to the bladder or may involve one or both kidneys in more severe cases.
In older cats, blood in the urine may be a sign of a UTI. In advanced cases of kidney infection, the owner/guardian may tell me, "My cat hangs his head over the water dish but won't drink very much."
If a cat has a UTI, you may notice symptoms like:
- Visible blood in the urine
- Weight loss
- Poor appetite
- Increased thirst
- Increased frequency of urination
- Straining to urinate
Treatment: Fortunately, bacterial urinary tract infections can usually be cleared with appropriate antibiotic therapy. In cases of kidney infection, antibiotics will need to be administered for at least four to six weeks.
Crystals in Urine
In younger cats, a common cause of bloody urine is the presence of crystals in the urine (crystalluria). These crystals can lead to a medical emergency when left undiagnosed and untreated.
Blocked urethra: In some male cats, crystals can cause blockage of the urethra. Because they can't urinate through a blocked urethra, this creates a medical emergency, rapidly leading to kidney failure and even death within 48 to 72 hours.
Stones: In female cats and some male cats, mineral crystals in the urine (typically, either calcium oxalate or struvite) can lead to the formation of stones but not urethral blockage.
These stones may be in the kidneys, ureters, or bladder. Stones can cause symptoms like:
- Blood in urine
- Chronic or recurrent urinary tract infection
- Loss of the kidney "upstream"
Treatment: Fortunately, ureteral stones are relatively rare. Special diets can help manage crystalluria and stones. However, calcium oxalate stones may require surgery.
Cystitis (FIC/FUS/FLUTD)
The third and most common reason for bloody urine is cystitis, which results in the inflammation of the bladder and urinary tract system. You may also have heard this condition called feline interstitial cystitis, feline idiopathic cystitis (FIC), feline urologic syndrome (FUS), or feline lower urinary tract disease (FLUTD).
Signs of feline interstitial Cystitis include:
- Blood-tinged urine
- Increased frequency of urination
- Straining to urinate
- Meowing while urinating
Treatment: This disease is diagnosed by excluding crystalluria, urinary tract stones, and urinary tract infection via analysis of urine, urine culture, and abdominal radiographs (x-rays) or ultrasound.
It is managed by diet modification, specifically by increasing canned food to increase the cat's hydration and thereby decrease the concentration of his urine.
Pain management can be an important part of treating cystitis. Additionally, environmental enrichment (more toys, cat perches, less stress) may help reduce the frequency of episodes of painful and bloody urination caused by interstitial cystitis.
Other causes of blood in cat urine
While rare, hematuria could also be a symptom of other conditions, so it's important to see your vet if you notice changes in your cat's urine. In addition to UTIs, stones, and cystitis, bloody urine can be a sign of several other conditions, including:
- Pandora Syndrome
- Bacterial infection
- Cancer of the bladder
- Anatomical abnormalities in young cats
- Urethral obstruction
- Diabetes
- Hyperthyroidism
- Constipation
- Tumors
- Injuries
Diagnosing Bloody Urine in Cats
To better understand your cat's health, your veterinarian will collect information through the following:
- Medical history: Questions about past health concerns and any physical or behavioral changes you've noticed
- Physical exam: Careful examination of your cat's eyes, mouth, ears, fur, and stomach
- Bloodwork: Small samples of blood will be taken and tested in a lab
- Urinalysis and urine culture: Testing your cat's urine to help identify or rule out certain conditions (like UTIs)
- X-rays and ultrasound: Equipment used to take pictures of the inside of your cat's body can help your vet locate stones
What to Do If Your Cat is Peeing Blood
While the cause of hematuria is often easily treatable, bloody urine can be a sign of a medical emergency or a more serious condition. So, if you see blood in your cat's urine or notice other behavioral changes, don't wait to get them checked out by your veterinarian.