Bloody Urine (Hematuria) in cats

Author: Dr. med. vet. Gisa Löwe | Last modified: 17.02.2026
Table of contents

When to visit the vet?

Urgent see a veterinarian within 24 hours

?

If the condition worsens / symptoms persist, consult a veterinarian.

Unsure about what’s wrong with your pet? Feel free to use our Symptom Checker for more clarity

Definition

Hematuria in cats refers to the presence of blood in the urine, which becomes visible through a reddish or brownish discoloration of the urine. It can be a symptom of various health problems, ranging from mild to severe conditions.

Can Occur with the Following Diseases:

Basics and possible causes

Hematuria in cats can be caused by various factors. One of the most common causes is a lower urinary tract infection, which can affect both the bladder and the urethra. Bacterial infections often lead to inflammation of the bladder lining, which can damage blood vessels and thus allow blood to enter the urine.

Another common reason for bloody urine in cats is urinary stones. These can occur in any region of the urinary tract, with the bladder and urethra being most commonly affected. The stones can irritate and injure the mucous membrane, which also leads to Bleeding.

Traumas, such as those caused by falls or accidents, are also potential causes of hematuria. Such mechanical trauma can directly affect the kidneys or bladder and lead to Bleeding in the urine.

Another cause is Tumors in the urinary tract. Both benign and malignant Tumors can alter the structure of the urinary tract and cause Bleeding. Older cats are particularly susceptible to tumor diseases.

In addition to these physical causes, systemic diseases such as blood clotting disorders can also lead to hematuria. These disorders can be congenital or caused by poisoning or certain medications.

Typical accompanying symptoms

  • Increased urination: Cats with hematuria often show an increased need to use the litter box. This can indicate irritation of the bladder.
  • Painful urination: If a cat experiences Pain during urination, it often manifests as meowing or whining during litter box visits. This can indicate cystitis or urinary stones.
  • Urine discoloration: The most obvious sign of hematuria is a reddish or brownish discoloration of the urine. The presence of visible blood is a direct symptom.
  • Behavioral changes: Cats may interact less socially than usual due to Pain or discomfort, or become irritated or lethargic.
  • Loss of appetite: Accompanying the other symptoms, a cat may eat less or stop eating altogether, indicating general discomfort.

When to see a vet?

Eskalation: RED if straining without urine, frequent unsuccessful litter box visits, severe abdominal Pain, Vomiting, apathy, or in male cats due to obstruction risk.

A vet visit is urgently required if a cat shows bloody urine, as this can indicate a serious illness. Even if the symptom does not immediately appear life-threatening, it is important to diagnose and treat the underlying cause.

If the cat also shows other symptoms such as Pain, significantly reduced appetite, or apathy, the visit to the vet should not be delayed. This could be an indication of a systemic illness or an acute infection that requires prompt therapy.

Especially in older cats or those with pre-existing conditions, it is important to act quickly, as they are more susceptible to complications. Even in young cats, prompt intervention can prevent an initial problem from developing into a major health challenge.

Symptom recognition for the pet owner and veterinary diagnostic procedure

For the pet owner, it is important to observe carefully when and how often the cat urinates, and whether the urine has an unusual color. Close observation of the cat’s behavior, including its eating habits and general activity, can also provide important clues.

The veterinary diagnosis process usually begins with a thorough physical examination and a detailed medical history. The vet will ask questions about the symptoms you’ve observed, your cat’s diet, and its general behaviour.

To confirm hematuria and determine the cause, the vet will likely perform a urinalysis. This includes tests for the presence of blood, bacteria, and crystals, which can indicate urinary stones. A urine culture may be performed to identify specific bacteria.

In addition, imaging procedures such as X-ray or ultrasound may be used to examine the structure of the urinary tract and look for stones or Tumors. Blood tests may also be necessary to rule out systemic causes and assess the cat’s overall health.

What the pet owner can do and professional therapy options

If you notice that your cat has bloody urine, you should first ensure that they have access to sufficient fresh drinking water. Adequate fluid intake can help flush the urinary tract and prevent the formation of crystals.

Monitor your cat closely and note any changes in behavior or symptoms. This information can be very helpful during a vet visit.

Avoid giving your cat medications or supplements without veterinary advice, as these may worsen the problem or cause other health problems.

Keep the litter box clean and easily accessible to avoid additional stress for the cat. A clean environment can also help prevent infection.

Outlook on current research

Research into bloody urine or hematuria in cats is continuously evolving to better understand the underlying mechanisms and find effective therapy options. An important area of research focuses on the role of inflammatory conditions and their influence on the occurrence of hematuria. Scientists are investigating the various inflammatory mediators active in the bladder wall and how these processes can be influenced by genetics factors, dietary habits, or environmental conditions.

Another focus of current research is on identifying specific biomarkers in the blood or urine that can indicate the presence and severity of hematuria. These biomarkers could help veterinarians make diagnoses more quickly and accurately, which is particularly important in cats, who often show subtle symptoms and for whom access to diagnostic procedures can be more difficult.

The role of nutrition in the development of hematuria is also being intensively researched. Special diets that influence the pH value of the urine are being investigated for their effectiveness. These diets could help prevent the formation of crystals and stones that can lead to mechanical irritation of the bladder wall and cause hematuria.

Genetics also plays a significant role in research into hematuria in cats. Studies are investigating genetic predispositions that could make some cat breeds more susceptible to bladder problems. By understanding these genetics factors, researchers hope to develop targeted prevention strategies to minimize the risk of hematuria.

Behavioral research is investigating how stress and anxiety in cats can contribute to the development of hematuria. Researchers are analyzing how environmental adaptations and stress-reducing measures influence the occurrence and frequency of hematuria. These studies are particularly relevant as cats are very sensitive to changes in their environment.

In addition, the effectiveness of new drug therapy is being intensively researched. These include medications that regulate the inflammatory process in the bladder or support Pain relief. The development of medications specifically tailored to the physiological needs of cats is a promising area of veterinary research.

The importance of long-term studies should not be underestimated. Such studies provide valuable insights into the natural course of hematuria in cats and the long-term effects of various therapy approaches. Long-term observations help to analyze relapse rates and evaluate the effectiveness of prevention measures.

An emerging area of research is the development of non-invasive diagnostic techniques that allow hematuria in cats to be diagnosed more quickly and with less stress for the animal. Imaging procedures, such as ultrasound and special urine tests that are less burdensome, are constantly being improved and tested.

Overall, the research aims to gain a more comprehensive understanding of the complex interactions between genetics, environmental, and physiological factors that contribute to the development of hematuria in cats. By integrating multidisciplinary approaches, scientists hope to significantly improve the prevention, diagnosis, and therapy of these distressing symptoms.

Frequently asked questions

  1. What is hematuria in cats? Hematuria in cats refers to the presence of blood in the urine, which is often visible through a reddish or brownish discoloration of the urine.

  2. Can bloody urine in cats disappear on its own? In some cases, hematuria may resolve on its own, especially if it is caused by temporary irritation. However, an examination by a veterinarian should be performed to rule out serious causes.

  3. How is hematuria diagnosed in cats? To diagnose hematuria, a urinalysis is usually performed, which confirms the presence of blood in the urine. Further tests such as blood tests or ultrasound may be necessary to determine the cause.

  4. What symptoms occur together with hematuria? In addition to bloody urine, cats may show increased urination, Pain when urinating, frequent toilet visits, or general Restlessness.

  5. Can stress cause hematuria in cats? Yes, stress can be a trigger for hematuria, as it can lead to inflammation of the bladder. Stress management can therefore be an important part of the therapy.

  6. What role does nutrition play in hematuria? Diet can have a significant impact on the formation of urinary crystals and stones that can lead to hematuria. A special diet can help minimize the risk.

  7. Is hematuria in cats an emergency? If a cat has bloody urine, it should be presented to a veterinarian immediately. While it is not always an emergency, it can indicate serious health problems that need to be treated.

  8. Can hematuria in cats be prevented? Prevention is not always possible, but regular veterinary check-ups, an adapted diet, and stress management can help reduce the risk.

  9. What treatments are available for hematuria in cats? The treatment depends on the cause. It can include the administration of antibiotics, Painkillers, special diets, or even surgical interventions if stones or Tumors are the cause.

  10. How can cat owners reduce stress in their animals? To reduce stress, cat owners should ensure a stable, predictable environment, provide retreats, and avoid sudden changes in daily routine.