Hemoglobin in the urine, known as hemoglobinuria, is a medical condition commonly referred to as blood in the urine. Hemoglobin is a protein found in red blood cells, which is responsible for carrying oxygen throughout the body. Under normal conditions, no hemoglobin should be found in the urine of cats or other companion animals. Hemoglobin is generally detected in the urine during a urinalysis. Hemoglobinuria occurs when red blood cells break down and hemoglobin is not reabsorbed by the kidneys. Myoglobin is a protein very similar to hemoglobin that can cause a false positive for hemoglobin in the urine during urinalysis. If hemoglobin is present in the urine, your pet will require medical diagnosis and treatment to prevent potentially severe issues.

The most obvious symptom of hemoglobin in the urine is discoloration. Hemoglobin gives red blood cells their color, so it can darken the urine or add a pink or red tinge to it. Other symptoms associated with hemoglobin in urine are similar to symptoms of anemia. Depending on the underlying cause of hemoglobin in the urine, cats and other companion animals may present with various other symptoms. 

Symptoms include:

Hemoglobin is generally present in the urine as a symptom or side effect of another medical condition. A variety of issues can result in hemoglobinuria, ranging from injuries to infections to genetic disorders. Some common causes of hemoglobin in urine in cats include:

Hemoglobinuria is often a symptom of an underlying condition. Your veterinarian will use a variety of diagnostic methods to determine why hemoglobin is present in your pet’s urine. This will include reviewing your cat’s complete medical history, discussing any symptoms you have observed, and conducting a full physical examination. Urinalysis is the most common diagnostic technique used to identify hemoglobin in urine and begin to diagnose the underlying cause. A urine sample will be taken, and laboratory urinalysis will be performed. The urinalysis will look for blood and bilirubin. Urine samples will also be tested for protein, glucose, and ketones. Veterinary staff may also complete a urine culture and urine cytology. 

Veterinary staff will also likely perform blood analysis after drawing a blood sample from your cat. Blood samples will be tested for complete blood count, biochemistry and electrolyte panels, signs of anemia, and signs of infection. Other diagnostic methods your veterinarian may use include x-rays, ultrasounds, and other imaging techniques that will let them get a closer look at the internal organs that could be affected. This will help determine where the blood is coming from, look for signs of trauma, and rule out tumors. By using multiple diagnostic methods, your veterinarian should be able to determine why hemoglobin is present in your pet’s urine and decide on the proper course of treatment.

The treatment methods your veterinarian uses may vary considerably depending on the underlying cause of their condition. In some cases, their condition will be simply treated with fluid therapy and rest. Other conditions that cause hemoglobinuria may require medical treatment or potentially even surgical intervention. Common treatments used specifically for hemoglobin in urine that may be used include:

Fluid therapy is a common treatment to alleviate dehydration, prevent shock, and maintain the function of a variety of bodily systems. If your cat has not been eating, is losing fluid, or is exhibiting signs of lethargy or weakness, IV fluids may be used. This treatment is commonly provided on an inpatient basis and carries a low risk. 

If blood loss is severe, a blood transfusion may be recommended to improve your cat’s condition. The primary risk associated with a blood transfusion is a blood type mismatch. Veterinary staff will determine your pet’s blood type and use proper methods to prepare and provide the transfusion in order to limit the risk to your cat. 

Your cat’s prognosis for recovery will depend greatly on the condition causing hemoglobin to be present in their urine. If the condition is treatable and your pet responds well to treatment, the prognosis is usually good. Certain conditions, including genetic ones, may be untreatable. In these cases, the prognosis will be guarded. While your pet is undergoing treatment and recovering, avoid stress, excitement, and changes to their environment. It is also a good idea to ensure your pet gets plenty of rest and limits the amount of exercise they are getting. Keep food, water, and the litter box nearby to prevent unnecessary movement. Be sure to follow your veterinarian’s instructions regarding home care, medication dosing, and follow-up visits.