Blood in Urine (Hematuria/Hemoglobinuria/Myoglobinuria) in Cats

Key Takeaways

Blood in the urine is primarily identified by pet parents once visible to the naked eye. 

• Blood in the urine is a common symptom in cats and it can have a multitude of causes which vary from mild to deadly if left untreated

• Urinalysis, blood work, and physical examination can determine the root cause 

• Treatment and prognosis depend on the underlying cause

A Closer Look: What is Blood in Urine in Cats?

Bloody urine in cats is fairly common and the causes of blood in the urine can vary in severity from mild to dangerous. Once blood is observed, pet parents should contact a vet as soon as possible. Blood in the urine can be divided into three categories which are determined through laboratory analysis of the urine:

Hematuria: the presence of whole red blood cells in the urine.

Hemoglobinuria: the presence of hemoglobin (from broken down red blood cells) in the urine.

Myoglobinuria: the presence of myoglobin (from the breakdown of muscle tissue) in the urine.

Possible Causes

Blood in urine is associated with a number of different conditions, including:

• Feline idiopathic cystitis (FIC) • Bladder stones and crystals (urolithiasis) • Urethral obstruction • Injuries

• Infections in the bladder, kidneys, or prostate (cystitis, nephritis, and prostatitis) • Other types of kidney diseases

• Tumors and cancer• Thromboembolism (saddle thrombus) • Toxin exposures, including anticoagulant rodenticides

• Severe muscle damage • Snake envenomation • Autoimmune hemolytic anemia • Immune mediated thrombocytopena

Risk Factors

Severity of illness indicated by blood in urine varies widely based on the root cause. For example, FIC is common and can be managed with relative ease and lifestyle monitoring, while ingestion of rat poison is deadly and requires rapid intervention.

Severity can also vary based on the origin of the bleeding. Blood may originate in the urinary tract but may also be vaginal, uterine, prostatic, or the result of a bleeding disorder.

Testing and Diagnosis

After a medical history and physical examination is done, diagnostics for blood in urine include:

• Bloodwork • Urinalysis • Diagnostic imaging

Most cases of bloody urine in cats are the result of FIC and are treated with medications including analgesics and antidepressants, and other medications along with nutritional management and environmental modification. Surgery is necessary for stones and urethral flushing is necessary for obstructions. Treatment varies widely for the other, less common causes of bloody urine.

Similar symptoms

Bloody urine can be confused with normal bleeding from the uterus that occurs when unspayed female cats are in heat or experiencing the life-threatening condition pyometra. In healthy cats, the color of urine varies widely and other urine colors might be mistaken for bloody urine.

Associated Symptoms

Blood in urine is often associated with:

• Stranguria (straining to urinate) • Pollakiuria (urinating in small amounts more frequently) • Abdominal pain

• Dysuria (difficulty urinating or pain while urinating) • Vocalization • Increased drinking

• Bleeding from other areas (eyes, nose, ears, gums, rectum)

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