Cat Peeing Blood But Acting Normal: When to be Concerned

Seeing blood in your cat’s urine can be pretty shocking. Even if your cat seems to be acting normal, bloody urine is NEVER normal. Most veterinarians recommend your cat be seen immediately rather than waiting until any other symptoms develop.

Bloody urine can be caused by various diseases, including:

  • bladder stones, stress,
  • blood clotting disorders, and
  • idiopathic cystitis.

This article will explain some possible causes for blood in your cat’s urine when they are acting fairly normal. Keep in mind, though, that your cat’s condition can change quickly depending on the cause. Even if they are acting normally, it is best to have them evaluated and treated. 

What are the common causes of blood in a cat’s pee? (Assuming your cat is acting normal)

Many cats with blood in the urine have a condition called idiopathic cystitis, an inflammatory process in the bladder that often causes discomfort and straining but is not caused by bacteria. One study demonstrated that nearly half of the cats evaluated for urinary tract issues had idiopathic cystitis. This condition is poorly understood but is thought to have multiple factors, including stress and environmental causes. 

There are a variety of different reasons your cat might have blood in its urine, including: 

  • Kidney (nephroliths) or bladder stones (uroliths) – kidney stones especially can cause blood in the urine without other symptoms, while bladder stones often cause discomfort and straining. 
  • Stress-induced – what we as owners don’t think of as stressful (getting another pet, changing the brand or type of cat litter, moving the litterbox, construction in the house, new people), cats can find VERY stressful. Sometimes, this can result in blood in the urine, straining, and discomfort. 
  • Trauma
  • Neoplasia or cancer
  • Coagulopathies – conditions that affect blood clotting, such as low platelets (thrombocytopenia)

You must remember a critical piece of information if your cat is peeing blood – blood does NOT always mean an infection. In fact, bacterial urinary tract infections in otherwise healthy cats (with no other diseases) are relatively uncommon.

Symptoms to monitor

Remember, though, that in many of these conditions, your cat may exhibit other symptoms besides blood in the urine. Cats are often very good at hiding signs of discomfort or pain. For example, a cat with low platelets may have pale gums, weakness, and bruises on its body. 

In most of these causes for blood in urine, your cat could also:

  • exhibit discomfort or pain when trying to urinate
  • vocalize when urinating,
  • strain, or urinate outside the litterbox.
  • sit in the litterbox for long periods without producing urine.

All these symptoms, if observed, can help your veterinarian with diagnosis.

If my cat is acting normal, does it mean it is less serious?

If the blood in urine is caught early, your cat may appear normal. However, cats will often hide their symptoms as long as possible. And when our cats appear healthy, we have no need to follow them to their litterboxes to see if their behavior is different. Keep an eye on your cat to see if they:

  • are straining,
  • urinating more frequently,
  • urinating small amounts, or
  • vocalizing. 

This information will help your veterinarian with diagnosis.

Are the causes different for FEMALE and MALE cats peeing blood?

Female cats are more prone to urinary tract infections than male cats, although this is still not very common. Bladder and kidney cancers are rare in both female and male cats. 

While there is no gender predisposition for many causes of bloody urine, age may play a more prominent role. Idiopathic cystitis, for example, typically occurs in young to middle-aged cats and is rarely seen in cats older than ten years of age. 

Male cats with urinary discomfort (whether from idiopathic cystitis, stones, or infection) are more likely to have a urethral obstruction than females due to the narrow nature of the male urethra. Urethral blockages can happen quickly and is a medical emergency. If your MALE cat had a urinary blockage, you typically see them straining without producing ANY urine, vocalizing, and being in pain when picked up. In severe cases, they can vomit, become lethargic, and even develop heart arrhythmias due to electrolyte imbalance. These cats are typically NOT ACTING NORMAL. 

Signs that you need to call your vet (even when your cat acts normal)

If you notice blood in your cat’s urine, it is best to have them examined by a veterinarian – even if your cat seems otherwise normal. Blood in the urine is NOT normal at any time. Your cat may act normal but actually be quite painful or uncomfortable. Certain causes can progress quickly and become life-threatening (like a urethral obstruction or urinary blockage in a male cat). 

If your cat is displaying any of the following symptoms, you should get them to your veterinarian as soon as possible: 

  • Straining
  • Vocalizing
  • Urinating small amounts frequently
  • Discomfort when picked up

Signs that blood in a cat’s pee is an emergency (even when my cat acts normal)

Some cases of blood in the urine require more immediate attention and shouldn’t wait until the next available appointment. If you notice any of the following symptoms, you should have your cat seen as soon as possible: 

  • Vomiting
  • Lethargy 
  • Not able to produce any urine or only dribbling 
  • Bruising anywhere on the body – This can be hard to see on some cats depending on the color of their skin and the thickness of their hair. The gums (if they are not pigmented or black) are a good spot to look for petechiae, or tiny little red spots on the gums. The inside of the ears, abdomen, and groin are also good places to check. Bruising can indicate blood conditions like low platelets that can inhibit clotting. 

What does blood in cat urine look like?

Blood in a cat’s urine may appear as pink, red, or brownish in color, and can sometimes be difficult to detect if there is only a small amount present. In some cases, the urine may also appear cloudy or have a strong odor. Below is an example picture:

red-colored cat pee indicating presence of blood in urine


  • Dr Sarah Graves

    Dr. Sarah Graves has been a veterinarian for almost 10 years and graduated from one of the leading veterinarian schools in the world: the Royal Veterinary College at the University of London.

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