Hematuria in cats

Blood in Cat Urine-Causes, Symptoms & Treatment

Causes            Symptoms           Diagnosis            Treatment

Blood in cat urine

At a glance:

  • About: Blood in the urine is medically called hematuria. It may be seen in the urine or picked up during a urine test. It is a symptom of a disease and not a disease in itself.
  • Symptoms: May not be apparent, or you may notice a red colour to the urine. Other symptoms will vary depending on the underlying cause.
  • Diagnosis: Baseline tests, diagnostic imaging and blood clotting tests.
  • Treatment: Address the underlying cause.


Hematuria is the presence of red blood cells in the urine. It is a symptom of an underlying disorder and isn’t a disease in itself. As are many causes of hematuria in cats ranging from mild to severe and life-threatening, prompt veterinary attention is required. It can be classified as microscopic or gross.

  • Microscopic hematuria: The urine pears normal but upon microscopic examination,  red blood cells are found to be present.
  • Gross hematuria: The cat’s urine is visibly discoloured due to the high numbers of red blood cells.


There are many possible causes of hematuria in cats, some of which include:

  • Kidney stones
  • Kidney tumour
  • Glomerulonephritis
  • Trauma such as car accident or a heavy fall
  • Blood clotting disorders such as disseminated intravascular coagulation, thrombocytopenia (low blood platelets) or rat poisoning
  • Bladder stones, infection or tumour
  • Urinary tract infection
  • Congenital urinary tract abnormalities
  • Cancer of the urinary tract
  • Poisoning (such as rat poison which leads to blood clotting disorders
  • Polycythemia (increased red blood cells)
  • Certain medications
  • Idiopathic (no known cause)

Accompanying symptoms:

Hematuria may often be accompanied by other symptoms, some of which include:


Your veterinarian will perform a physical examination of your cat and obtain a history including accompanying symptoms you may have noticed. Blood which is present only at the beginning of urination may suggest bleeding from the lower urinary tract, bleeding which is present at the end of urination may point to bleeding from the upper urinary tract and bleeding that is present throughout the urine is likely to originate from the kidneys, ureters or bladder. These can all help your veterinarian narrow down the cause of hematuria. He may wish to run the following tests to determine the cause of the hematuria:

Your veterinarian will need to run the following tests to determine the cause of the hematuria:

  • Urinalysis: The presence of white blood cells may indicate urinary tract infection. Protein in the urine may indicate kidney disease.
  • Complete blood count: to check for anemia, white blood cells, red blood cell casts, and cancer cells.
  • A biochemical profile: To evaluate kidney function:
  • Abdominal ultrasound: To look for for stones, tumours, and kidney size.
  • Intravenous pyelogram (IVP): This is a contrast x-ray examination of the kidneys, ureters, and bladder. A contrast material is injected into the patient and collects in the kidneys and urinary tract. This allows the veterinarian to assess the kidneys and urinary tract.
  • Blood clotting tests: Prothrombin time and activated partial thromboplastin time.


Treatment depends on the cause of the hematuria and may include:

Urinary tract infection:

Antibiotics to kill the bacteria and increasing water consumption such as switching to a wet diet and introducing a water fountain. Keep litter trays clean at all time.


A completely blocked cat will need to have urine removed via a needle inserted directly into the bladder or catheterisation. Home care includes a stone dissolving prescription diet and increasing water consumption to dilute the urine and prevent the formation of crystals. Stones which can’t be dissolved will need surgical removal.

Bladder and kidney stones:

Prescription diet to dissolve the stones. Urinary acidifiers to change the urine pH and if the stones cannot be dissolved, surgical removal will be necessary.


Surgery to remove cancer. Chemotherapy and/or radiotherapy may also be given.

Blood clotting disorders:

Treatment depends on the underlying cause but may include injection of vitamin K, corticosteroids to slow down platelet destruction and blood transfusion where necessary.

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