Hematuria (Blood in Urine) in Dogs

Hematuria is the presence of red blood cells in the urine. It may be gross (visible to the naked eye) or microscopic. Possible causes of hematuria include:

Bacterial infections of the urinary and genital tracts such as cystitis (bladder infection), vaginitis or prostatitis

Cancer of the urinary or genital tracts

Calculi (stones) in the urinary tract

Congenital urinary tract abnormalities (those present at birth)

Rare parasites of the urinary tract

Clotting (bleeding) disorders including anti-coagulant rat poison (warfarin)

Trauma

Normal reproductive or heat cycles (estrus)

Medication-induced (e.g., cystitis caused by cyclophosphamide, a drug used to treat some types of cancer and immune-mediated diseases)

Benign idiopathic ("of unknown cause") hematuria originating from the kidney

What to Watch For

The effect of hematuria on the pet may range from no obvious effect to severe. Severe bleeding into the urinary tract may cause the dog to become anemic and may cause weakness or collapse.

Other symptoms that commonly accompany hematuria include:

Painful or difficult urination

Straining to urinate

Frequent passage of small amounts of urine

Abdominal pain

You should have your pet examined by your veterinarian if you observe hematuria or any of these other symptoms.