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Haematuria in Cats - Blood in Cats Urine

What is Haematuria?

Haematuria is the medical name for blood in the urine. There are many reasons why cats can get blood in their urine, some of which are more serious and urgent than others.

What Causes Haematuria in Cats?

  • Infection (of the urethra or bladder) – also known as “cystitis”.

  • Bladder stones

  • Tumour of the bladder or urethra

  • Kidney disease

  • Idiopathic feline lower urinary tract disease (iFLUTD)

  • In male cats specifically =

    • Prostatic disease (inflammation or tumour)

  • In female cats =

    • Can be mistaken for being in season

What Should I do if I See Blood in my Cats’ Urine?

If you notice blood in your cat’s litter tray it is imperative that you call your vet and get your cat looked at. They could be in a lot of discomfort and pain because of this, and most conditions are best caught and treated earlier rather than later.

In order to help your vet as much as possible try to consider the following questions:

  • Does your cat look uncomfortable when urinating or defecating recently?

  • Does their back look arched?

  • Are they in their litter tray longer than usual?

  • Are they missing the litter box? Or going to the toilet in unusual places?

  • Have there been any obvious changes in the home such as a new cat or dog?

What Tests Will The Vet Carry Out?

After asking you some more questions about the general health of your cat and narrowing down any possible causes, they may consider performing the following investigations, depending on what they believe to be the most likely cause:

Blood Test

  • This blood test will consist of a complete blood count and a biochemistry.

  • The main aims of the complete blood count are to assess:

    • the white blood cells for signs of inflammation or infection

    • the red blood cells for signs of anaemia or dehydration

  • On the biochemistry we are most worried about these parameters being high:

    • BUN (blood urea nitrogen)

    • Creatinine

      • When this level is elevated, we call this azotemia

      • The degree of azotemia (i.e., amount of creatinine) helps us to determine the degree of severity of kidney damage

  • There is an additional test which we can run on cats called SDMA, which helps us to detect kidney disease much sooner than your regular blood tests.


  • An ultrasound of the abdominal cavity will be performed to assess the kidneys and the bladder, as well as the prostate in male cats.

  • Abnormalities of the kidneys such as shrinking of one kidney compared to the other, as well as the internal architecture can be assessed. This gives us information about diseases such as chronic kidney disease, where the size of the kidneys often shrinks and there is loss of this architecture. We are also able to assess for any stones, masses or inflammation in the bladder.


  • X-rays of the abdomen are taken initially in order to get a wider view of what is happening inside the abdomen. This will help us to determine if the bladder and kidneys are grossly enlarged or if there are any obvious masses inside the abdomen which could help us to narrow down what the cause of the haematuria could be.

  • More advanced radiography involves the use of contrast agents which are given to your cat via a catheter in the arm. The contrast allows us to examine the flow of the urine from the kidneys to the bladder as well as examine the bladder wall.

Urine Sample

  • This can be collected by the vet by placing a needle into the bladder and collecting the sample directly (cystocentesis) or by putting a special litter into your cat’s litter box which doesn’t absorb urine, allowing you to collect it.

  • This urine is then checked using a urine dipstick and a refractometer

    • The urine dipstick helps us test the urine for = blood, protein, pH (acidity and alkalinity), glucose, ketones, bilirubin and urobilinogen. This gives us an understanding of the pathology, which we use in combination with the blood test results.

    • The refractometer helps us to determine the specific gravity of the urine (USG), i.e., the concentration of the urine. This allows us to assess the functioning of the kidneys.

What are the Potential Treatments for Haematuria?

The treatments greatly depend on the cause of the haematuria and the individual patient and owner.

If your cat is suffering from cystitis or idiopathic feline lower urinary tract disease (iFLUTD) then often the home environment may need to be adjusted in order to reduce any possible stressors to your cat. These changes will include ensuring there is 1+ litter trays, food bowls and water bowls for the number of cats in the home. For example, if you have 2 cats then you will need 3 litter trays, 3 food bowls and 3 water bowls. This is often one of the biggest stressors for cats because they do not like to share their resources with others.

Cats also like to be able to get away from each other and hide, therefore providing separate areas where they can hide away from each other will help to keep the tension low in the home.

An addition to these changes could be adding pheromone therapies to the home, such as Feliway, which has been proven to reduce anxiety in cats, especially in multi cat households.

If a stone is found within the bladder, then surgery may be necessary to remove this if the vet believes your cat cannot pass this by themselves. Likewise, if a tumour / mass is found, the location of this will dictate if surgery is possible, and chemotherapy or radiography may be considered by your vet. It is always important at this point to consider the quality of life of your beloved furry friend and consider whether invasive procedures would be too much for them to handle and whether euthanasia is the kindest treatment.

This can be a very hard decision to make, your vet will talk you through the treatments available for your pet and their individual condition and help you come to the best treatment decision.


  • Never ignore blood in your cat’s urine

  • Act quickly and seek your Vet’s advice

  • Improve the home environment to keep stress to a minimum

  • You know your cat best and it is important to make note of any changes in behaviour and worrying signs and contact your vet about your concerns so that they can talk you through it and together make your pet be as comfortable as possible.


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