Blood in Urine (Hematuria/Hemoglobinuria/Myoglobinuria) In Dogs

Summary

Bloody urine is red, pink, or brown-tinged. This symptom is uncommon in dogs, but indicates potentially serious underlying diseases. Dogs with bloody urine require prompt veterinary care to determine the cause of their symptoms. Other symptoms associated with bloody urine include straining to urinate, urinating frequently in small amounts, or painful urination. 

The first step in diagnosing apparently bloody urine is to determine what is present in the urine to give it a red color. Healthy urine that appears dark may be mistaken for bloody urine. If testing shows traces of blood are actually present in the urine, this indicates a variety of potentially serious medical conditions. 

Treatment protocols for apparently bloody urine depend on the underlying condition diagnosed, and vary widely.

Guidelines

Blood in the urine is uncommon in dogs, but indicates potentially  serious diseases including tumors, bleeding disorders, infections, and traumatic injury. Dogs with red, pink, or brown-tinged urine require prompt veterinary care. 

In some cases, bloody urine is an emergency. Dogs showing the following symptoms, along with bloody urine, require immediate emergency veterinary care:

• Pale gums • Difficulty breathing • Extreme lethargy

Possible Causes

Urine appears bloody as a result of the presence of either whole red blood cells in the urine or compounds from the breakdown of blood cells or muscle tissue.

Red pigment in urine falls into three general categories: hematuria, hemoglobinuria, and myoglobinuria. Each of these are associated with different underlying conditions. 

Hematuria is a result of bleeding into the urinary tract.  It is indicative of a variety of conditions including: 

• Thrombocytopenia • Vasculitis • Toxicities such as rodenticides • Multiple conditions associated with the kidney, urinary tract, or bladder 

• Traumatic injuries • Prostate disease • Vaginal or uterine disease • Normal estrus in intact female dogs

Hemoglobinuria usually occurs when. red blood cells are destroyed, and free hemoglobin is excreted into the urine through the kidneys. Hemoglobinuria is indicative of the following conditions:

• Toxicity such as acetaminophen, copper, zinc, onions/garlic or snake venom • Infections affecting red blood cells like babesiosis • Immune-mediated hemolytic anemia

• Neonatal isoerythrolysis • Heatstroke

Myoglobinuria occurs when myoglobin is released into the bloodstream after muscle damage andis similarly filtered out by the kidneys. Myoglobinuria indicates:

• Extreme exertion or extreme body temperature • Muscle infection• Muscle damage from toxins or traumatic injury • Genetic diseases that affect muscle

Abnormal bleeding disorders (coagulopathies) may also lead to blood in urine.

Risk Factors

In general, the color of bloody urine does not indicate the severity of the underlying condition. Urine with hemoglobinuria is more likely to be pink to red-brown compared to hematuria, which is typically a brighter red.

Testing and Diagnosis

The first step in diagnosing bloody urine is to identify which of the three categories the blood traces in the urine point to.

Once the source of the red color is categorized, further diagnostics are required to determine what the underlying condition is. These include, but are not limited to:

• Physical exam • Routine blood tests  • Urine protein/creatinine ratio evaluation Blood clotting profiles • Diagnostic imaging like x-rays and ultrasound • Urine culture 

• Genetic testing • Biopsy

Treatment for hematuria, hemoglobinuria, or myoglobinuria depends on the underlying condition identified.

Similar symptoms

Bloody urine, whether due to whole blood or hemoglobin, is easily identified by owners. In some cases, dark brown or chocolate-colored urine can be mistaken for bloody urine. This usually results from genetic conditions or toxicities that lead to the presence of methemoglobin in the urine. Dark urine with no traces of blood may also be healthy and not indicative of a problem at all.

Associated Symptoms

The symptoms most often seen alongside bloody urine are:

• Straining to urinate (stranguria) • Urinating frequent, small amounts (pollakiuria) • Painful urination or difficulty urinating (dysuria)

Dogs exhibiting any of these symptoms require prompt veterinary care.  Some dogs with bloody urine show no other symptoms.