Hematuria in Dogs & Cats – When Your Pet Pees Blood

If you’re like me, you don’t monitor every elimination your
dog or cat makes. You don’t observe every urination. Yet at some point in a pet’s
life, they will inevitably develop blood in their urine. This is a condition
called hematuria. It’s actually pretty common, so I wanted to dedicate some
time explaining this important medical issue. I hope you find the information
useful and shareworthy. Happy reading!


Hematuria – What is it?

To understand hematuria, one should have an appreciation of
basic urinary tract anatomy. The urinary tract starts with the kidneys, the
organs that make urine. Urine then travels from the kidneys to the urinary
bladder in small tubes called ureters. Urine is stored in the urinary bladder
until an animal urinates. During urination, urine is expelled from the urinary
bladder through a tube called the urethra to the outside world.

Normal anatomy of a dog’s urinary tract. Image courtesy of DogHealth.com

Hematuria simply means there are red blood cells in the
urine. It’s a pretty straightforward definition. What isn’t always as
straightforward is the cause of a pet’s hematuria. In fact, any of the urinary organs
– kidneys, ureters, urinary bladder, urethra – could be the source of a pet’s hematuria.
Furthermore, the genital tract is intimately associated with the urinary tract,
so problems in the vagina and vestibule of females or the prostate and prepuce
of males could also be a source of red blood cells in urine.

Regardless of organ involved, general processes that could
cause red blood cells to appear in urine are:

  • Infection (bacterial, parasitic, fungal)
  • Inflammation
  • Immune-mediated diseases
  • Trauma
  • Blood clotting abnormalities
  • Cancer

Hematuria – What does it look like?

As blood is red, one might assume urine with red blood cells
in them is similarly red in color. That’s true a majority of the time. But not
always! In fact, sometimes only a microscopic amount of red blood cells is
present, and thus urine appears grossly normal.

Gross hematuria vs. microscopic hematuria. Illustration courtesy of Harvard Health.

Often animals with hematuria have other clinical signs that
can give the doctor important clues about which genitourinary organ is involved
and what the underlying disease process is. Some of the important changes
veterinarians look and about which they ask questions are:

  • What is the volume of urine eliminated (e.g.: a normal
    volume vs. a larger/smaller volume)?
  • What does your pet’s urine stream look like
    (strong and steady throughout vs. small spurts, etc.)?
  • Does your pet need to urinate more frequently?
  • Does your pet seem to strain when urinating?
  • Does your pet leak urine while they’re walking?
  • Does your pet leak urine while sleeping?
  • Is the urine grossly abnormal?
  • If the urine is grossly abnormal in color, is the
    urine abnormal during the entire urine stream or only at the beginning or end?

Please be prepared to answer these questions, as your input
can be very helpful!

Hematuria – How is it diagnosed?

Of course, red colored is an obvious red flag for hematuria.
However, not all reddish urine is caused by red blood cells in the urine. A
simple, non-invasive urinalysis will help document the presence of red blood
cells in urine, and thus confirm a finding of hematuria.

Once hematuria is documented, a veterinarian will continue a
logical diagnostic process that will include blood and urine tests, as well as
diagnostic imaging. Commonly recommended tests include:

  • Complete blood count – to look for evidence of
    inflammation, anemia, and to measure platelets (initial clot-forming cells)
  • Biochemical profile – to evaluate protein
    levels, electrolytes, and kidney values
  • Urine culture – to document infection
  • Coagulation testing – to check a pet’s ability
    to clot blood properly
  • Abdominal imaging (i.e.: radiographs/x-rays +/-
    sonography) – to look for urinary stones and architectural changes in the
    urinary tract
Radiographic (x-ray) appearance of a dog’s urinary bladder containing bladder stones (blue arrow). Image courtesy of the American College of Veterinary Surgeons.

Most cases of hematuria are straightforward. However,
chronic hematuria can be troublesome and complicated. Pet parents may find it
helpful to partner with a board-certified veterinary internal medicine
specialist to develop a logical diagnostic plan.

Hematuria – How is it treated?

The specific way to treat hematuria depends on the
underlying cause. A bacterial urinary tract infection is treated with an
antibiotic. A coagulation disorder requires an infusion of a specific blood
product called plasma and sometimes the administration of vitamin K1. Some
urinary stones can be gradually dissolved with dietary manipulation over time
while others need to be surgically removed. Tumors should be surgically removed
whenever possible. Pet parents may find it helpful to partner with a
board-certified veterinary internal medicine specialist to develop an
appropriate treatment plan.  

The take-away message about hematuria in dogs & cats…

Hematuria or red blood cells in the urine is a common
problem encountered in feline and canine medicine. There are many possible
causes, ranging from infections to infiltrative cancers. A logical and thorough
diagnostic investigation is needed to ensure an accurate diagnosis is made and
the most appropriate therapies are initiated.

To find a board-certified veterinary internal medicine specialist, please visit the American College of Veterinary Internal Medicine.

Wishing you wet-nosed kisses,