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Reddish-brown Urine in cats

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

When to visit the vet?

Urgent see a veterinarian within 24 hours

EMERGENCY if weakness, collapse, difficulty breathing, severe pain, very dark cola-colored urine after trauma or heat exposure, or if obstruction is suspected.

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

Definition

Reddish-brown urine in cats is an anomalyAn anomaly is a deviation from what is considered normal or expected. In medicine, it often refers to unusual physical or genetic characteristics that may be present at birth or develop later. in which the cat’s urine takes on an atypical color, indicating the presence of blood or certain pigments. This can indicate various underlying health problems, ranging from harmless to serious conditions.

Can Occur with the Following Diseases:

Basics and possible causes

The normal color of cat urine is light yellow to amber and is caused by urochrome, a pigment produced during the breakdown of hemoglobinhemoglobin is an iron-containing protein in red blood cells responsible for transporting oxygen from the lungs to the body tissues and carbon dioxide back to the lungs.. A change in urine color can be caused by the presence of blood, hemoglobinhemoglobin is an iron-containing protein in red blood cells responsible for transporting oxygen from the lungs to the body tissues and carbon dioxide back to the lungs., myoglobin, or other pigments.

One of the most common causes of reddish-brown urine is hematuria, the presence of red blood cells in the urine. This can be caused by infections, inflammatory conditions, tumors, or injuries in the urinary tract.

Another cause could be hemoglobinuria, in which free hemoglobinhemoglobin is an iron-containing protein in red blood cells responsible for transporting oxygen from the lungs to the body tissues and carbon dioxide back to the lungs. is present in the urine. This occurs when red blood cells are destroyed in the blood vessels, which can lead to conditions such as hemolytic anemia.

Myoglobinuria, the presence of myoglobin in the urine, can occur when muscle tissue is damaged, which happens with traumas or certain muscular diseases.

Certain foods or medications can also cause urine discoloration, but this is less common.

Typical accompanying symptoms

Altered urine odor, which may smell stronger or unusual, potentially indicating infections or metabolicMetabolic refers to metabolism, i.e. the entirety of chemical processes that take place in a living organism to enable life processes. Metabolic disorders can cause a variety of Diseases in Dogs and cats. disorders.
Pain when urinating, recognizable by frequent meowing or restlessness during toileting, which may indicate cystitis or bladder stones (uroliths).
Increased or decreased urination, which may indicate kidney problems or diabetes.
Bloody urine, visible as distinct red or brownish discoloration in the litter or on the floor.
Loss of appetite, which may indicate general malaise or specific conditions such as renal failure.
Lethargy or weakness, which may indicate a systemic disease or anemia.
Fever, which could indicate an infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. affecting the urinary tract.

When to see a vet?

A veterinarian should be consulted if the reddish-brown urine does not disappear within a day or if other symptoms such as pain, fever, or lethargy occur. These symptoms can indicate serious health problems that require immediate medical treatment.

Especially in older cats or those with a historyThe medical history is the systematic collection of a patient's medical history through questioning. It includes information about previous illnesses, treatments, allergies, and lifestyle habits. of urinary tract infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease., a veterinarian should be consulted promptly to avoid complications or a worsening of the condition.

If the cat’s urine is clearly reddish or appears to contain blood, this is an emergency that requires immediate veterinary attention, as it could indicate severe bleeding or injury in the urinary tract.

Symptom recognition for the pet owner and veterinary diagnostic procedure

As a pet owner, you can monitor your cat’s urine color by regularly checking the litter for discoloration. It can be helpful to collect the urine in a clean, light-colored bowl to better assess the color.

The veterinarian will likely begin with a thorough physical examination and inquire about the cat’s medical historyThe medical history is the systematic collection of a patient's medical history through questioning. It includes information about previous illnesses, treatments, allergies, and lifestyle habits.. A urine test is crucial to determine whether red blood cells, hemoglobinhemoglobin is an iron-containing protein in red blood cells responsible for transporting oxygen from the lungs to the body tissues and carbon dioxide back to the lungs., or myoglobin are present.

Further diagnostic tests may include blood tests to check kidney and blood function, as well as X-rays or ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. examinations to identify structural anomalies or stones in the urinary tract.

In some cases, cystoscopyCystoscopy is a diagnostic procedure that uses a cystoscope, a thin tubular instrument with a camera, to directly view the bladder and urethra. It allows for the diagnosis of lower urinary tract conditions in dogs and cats, including Tumors, stones, and infections. may be necessary, in which a small camera is inserted into the bladder to allow direct visualization of the urinary tract.

What the pet owner can do and professional therapy options

As a first measure, the pet owner should ensure that the cat takes in sufficient fluids to flush the urinary tract. Fresh water should always be available, and it can be helpful to encourage the cat to drink more by providing water sources or drinking fountains.

It is important to monitor the cat and ensure that it urinates regularly. If it has difficulty urinating or shows signs of pain, this is an indicationIndication refers to a valid reason or rationale for using a specific treatment, medication, or medical procedure. It is based on the diagnosis and the patient's clinical condition. that immediate veterinary care is required.

A change in diet can be helpful, especially if the reddish-brown discoloration of the urine is due to bladder stones (uroliths). The veterinarian can recommend special diets that help reduce the risk of urinary tract problems.

Avoid giving the cat medication or supplements without veterinary advice, as this could worsen the situation.

Outlook on current research

Research on reddish-brown discoloration of cat urine is a dynamic field that focuses on the molecular and physiological basis of this symptomatologySymptomatology refers to the entirety of symptoms associated with a particular disease or condition. It describes how a disease manifests itself externally.. Scientists are investigating how changes in blood composition and metabolism in cats can lead to such discolorations. One focus is on the analysis of hemoglobinhemoglobin is an iron-containing protein in red blood cells responsible for transporting oxygen from the lungs to the body tissues and carbon dioxide back to the lungs., myoglobin, and bilirubinBilirubin is a yellow pigment that is produced when hemoglobin from red blood cells is broken down. It is further processed in the liver and then excreted via the bile. Elevated bilirubin levels may indicate liver dysfunction or impaired bile excretion., as these substances are frequently associated with urine discoloration. Recent studies have also examined the role of oxidative stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being. and cellularCellular refers to cells or consisting of cells. In biology and medicine, it refers to processes, structures, or functions that occur at the level of individual cells. damage to understand how these factors contribute to changes in urine color.

Another important aspect of research is the development of diagnostic tests to identify the causes of reddish-brown urine discoloration more quickly and precisely. Modern laboratory techniques such as massIn pathology, the term "mass" is used to describe an abnormal lump or growth in the body. A mass can form in the skin or subcutaneous tissue, or even inside the body. The causes can be benign (not cancer) or malignant (cancer). spectrometry and genome sequencing are being used to identify the specific markers associated with this symptom. These developments could enable early detection and targeted treatment in the future.

Researchers are also working on developing non-invasive monitoring methods to better monitor the health status of cats with this symptom. These methods could include regular monitoring of urine composition without the need for a veterinary visit. Such technologies are particularly promising for improving the quality of life of cats and reducing the stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being. associated with veterinary examinations.

Additionally, there are studies on genetic predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases. in different cat breeds, as some breeds are more susceptible to certain diseases associated with reddish-brown urine. This research could lead to the development of targeted breeding programs in the long term that minimize the risk of such symptoms occurring.

Finally, there are also studies examining the effects of diet on the urine color of cats. Certain foods and dietary supplements can influence the chemical composition of urine and potentially lead to discoloration. Researchers are investigating how specific dietary adjustments can help control or prevent this symptom.

Frequently asked questions

What does it mean if my cat’s urine is reddish-brown? Reddish-brown discoloration of cat urine may indicate the presence of blood or pigments such as hemoglobinhemoglobin is an iron-containing protein in red blood cells responsible for transporting oxygen from the lungs to the body tissues and carbon dioxide back to the lungs. or myoglobin. This can be caused by various health problems and should be examined by a veterinarian.
Is reddish-brown urine in cats always a sign of illness? While reddish-brown urine often indicates an underlying condition, there are also less serious causes such as certain dietary factors or medications that can discolor the urine. An accurate diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. is important.
What tests can be performed to determine the cause of reddish-brown urine? Veterinarians can perform a urinalysis to check the chemical composition of the urine. Blood tests, ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow., or X-rays may also be necessary to determine the underlying cause.
Can a cat’s diet cause reddish-brown urine? Yes, certain foods or dietary supplements can affect urine color. It is important to review the cat’s diet and adjust it if necessary to ensure it is not causing discoloration.
What diseases are commonly associated with reddish-brown urine? The most common conditions associated with reddish-brown urine include urinary tract infections, bladder stones (uroliths), poisonings, and certain blood diseases. Each of these conditions requires different diagnostic and therapeutic approaches.
Can stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being. in cats cause reddish-brown urine? StressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being. itself does not normally cause urine discoloration, but it can worsen health problems that lead to such symptoms. StressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being. management can be an important part of therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions..
How quickly should I take my cat to the vet if I notice reddish-brown urine? It is advisable to see a veterinarian as soon as possible if you notice a change in urine color. Early diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. can be crucial for successful treatment of the underlying cause.
Can reddish-brown urine in cats go away on its own? While some cases of discoloration may disappear without treatment, especially if caused by dietary factors, it is important to determine the underlying cause, as untreated health problems can lead to serious complications.
What role does geneticsGenetics is the science of genes, heredity, and the variation of organisms. It studies how genetic information is passed from generation to generation and how it influences the development, appearance, and behavior of living things. play in cat urine discoloration? Genetic factors can play a role, especially in breeds that are more susceptible to certain conditions. Research continues to investigate how genetic predispositions can influence the likelihood of discoloration.
Are there preventive measures to avoid reddish-brown urine in cats? A balanced diet, regular veterinary examinations, and stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being. management are crucial factors in minimizing the risk of health problems that can lead to reddish-brown urine. Good care and observation of the cat can help detect early signs of problems.