Blood in Your Dog's Urine: Causes and What to Do

Noticing blood in your dog's urine — known medically as haematuria — is understandably alarming. The urine may appear pink, red, orange-tinged, or even dark brown depending on the amount of blood present and where in the urinary tract it originates. In some cases, you may notice blood only at the beginning or end of urination, or it may be present throughout.

"Blood in the urine is always a signal that something needs investigation. While it can range from a simple urinary tract infection to something more serious like bladder stones or a tumour, it should never be ignored or assumed to be minor. A urinalysis and vet exam are essential first steps." — Dr. Sarah Chen, DVM

Haematuria can be categorised in two ways:

• Gross haematuria: Blood visible to the naked eye — the urine looks discoloured
• Microscopic haematuria: Blood cells detected only under a microscope during routine urinalysis, with no visible colour change

Both forms are clinically significant. Even microscopic haematuria found incidentally during a wellness check warrants further investigation, as it may indicate early-stage disease.

It's also worth noting that female dogs in heat can drip blood that mixes with urine, which owners sometimes mistake for haematuria. Similarly, bloody discharge from the prepuce in male dogs can contaminate urine samples. Your vet will consider these possibilities during examination. For a broader overview of urinary health, see our guide on urinary issues in cats and dogs.

There are numerous potential causes of haematuria in dogs, ranging from mild and easily treatable to serious and life-threatening. A thorough veterinary work-up is needed to determine the underlying cause.

Urinary Tract Infections (UTIs)

Bacterial UTIs are one of the most common causes of blood in dog urine, particularly in female dogs due to their shorter urethra. Bacteria ascend into the bladder and cause inflammation and bleeding of the bladder lining. Symptoms typically include frequent urination, straining, blood-tinged urine, and sometimes accidents in the house. UTIs are usually straightforward to diagnose with a urinalysis and culture, and respond well to appropriate antibiotic therapy.

Bladder Stones (Urolithiasis)

Mineral crystals can aggregate in the bladder to form stones of varying sizes and compositions. Struvite and calcium oxalate stones are the most common types in dogs. These stones irritate the bladder wall, causing inflammation, pain, and bleeding. Small stones may also lodge in the urethra, causing partial or complete obstruction — a medical emergency.

Other Important Causes

• Prostatic disease: In intact (unneutered) male dogs, benign prostatic hyperplasia, prostatitis, or prostatic cysts can cause haematuria
• Bladder or urethral tumours: Transitional cell carcinoma (TCC) is the most common bladder cancer in dogs, more frequently seen in certain breeds like Scottish Terriers, Shetland Sheepdogs, and Beagles
• Trauma: Blunt force injury to the abdomen or pelvis can damage the kidneys, bladder, or urethra
• Coagulopathies: Clotting disorders from rodenticide poisoning, immune-mediated thrombocytopaenia, or liver disease can cause bleeding anywhere, including the urinary tract
• Kidney disease or infection: Pyelonephritis (kidney infection) or kidney stones can cause blood that originates higher in the urinary tract

For a deeper dive into UTIs specifically, explore our detailed guide on UTIs in dogs: symptoms and treatment.

When you bring your dog to the vet for blood in the urine, expect a systematic diagnostic approach. The goal is to identify the source, severity, and underlying cause of the bleeding.

Urinalysis

This is the most important first-line test. A complete urinalysis examines:

• Colour and clarity: Visually assessing the degree of blood contamination
• Dipstick chemistry: Tests for blood, protein, glucose, pH, and other indicators
• Sediment examination: Microscopic analysis of red blood cells, white blood cells, bacteria, crystals, and casts
• Specific gravity: Measures urine concentration, which reflects kidney function

Ideally, the sample is collected via cystocentesis (a sterile needle directly into the bladder) to avoid contamination from the lower urinary tract or genital area. This method gives the most accurate results.

Urine Culture and Sensitivity

If infection is suspected, a urine culture identifies the specific bacteria involved and determines which antibiotics will be most effective. This is far more reliable than treating empirically based on urinalysis alone, as antibiotic resistance is an increasing concern.

Imaging

• Abdominal radiographs (X-rays): Excellent for detecting radiopaque bladder and kidney stones, and can reveal some bladder masses
• Abdominal ultrasound: Provides detailed images of the bladder wall, kidneys, prostate, and can detect stones, tumours, and structural abnormalities that X-rays might miss

Blood Work

A complete blood count (CBC) and chemistry panel assess overall health, kidney function, platelet count, and clotting ability. This helps identify systemic causes of haematuria such as clotting disorders or kidney failure. In older dogs, especially when a mass is suspected, additional tests like a coagulation panel or biopsy may be recommended.

Treatment for haematuria depends entirely on the diagnosis. There is no one-size-fits-all approach, which is why accurate diagnosis is critical before starting any treatment plan.

Treating UTIs

Bacterial urinary tract infections are treated with a targeted course of antibiotics, typically lasting 7-14 days depending on severity and location. It's essential to complete the full course of antibiotics even if symptoms improve quickly, as stopping early can lead to resistant infections. A follow-up urinalysis and culture 5-7 days after completing antibiotics confirms that the infection has been fully cleared.

Managing Bladder Stones

Treatment depends on the type and size of stones:

• Struvite stones: Can often be dissolved with a prescription dissolution diet over 4-12 weeks, combined with antibiotic therapy if a concurrent UTI is present
• Calcium oxalate stones: Cannot be dissolved and require surgical removal (cystotomy) or, in some cases, minimally invasive procedures like laser lithotripsy
• Prevention: After removal, dietary management and regular monitoring help prevent recurrence — specific diets and increased water intake are typically recommended long-term

For comprehensive information on stone management, read our guide to bladder stones in dogs: treatment and prevention.

Addressing Other Causes

• Prostatic disease: Neutering often resolves benign prostatic hyperplasia. Bacterial prostatitis requires prolonged antibiotic therapy (4-6 weeks or more)
• Bladder tumours: Treatment may include non-steroidal anti-inflammatory drugs (piroxicam or meloxicam), chemotherapy, or surgery depending on the tumour type and location
• Coagulopathies: Rodenticide poisoning is treated with vitamin K1 therapy, while immune-mediated conditions require immunosuppressive medication

While any blood in the urine warrants a vet visit, certain situations require emergency attention. Knowing these red flags can be life-saving.

Emergency Warning Signs

• Inability to urinate: If your dog is straining repeatedly but producing little or no urine, this may indicate a urinary obstruction — a life-threatening emergency that requires immediate veterinary intervention
• Large amounts of blood: Frank blood or blood clots in the urine suggest significant bleeding that needs rapid assessment
• Lethargy, vomiting, or collapse: These signs alongside haematuria suggest a systemic problem such as severe infection, poisoning, or internal bleeding
• Known toxin exposure: If your dog may have ingested rat poison or other anticoagulant rodenticides, seek emergency care immediately — symptoms can appear 2-5 days after ingestion
• Abdominal pain or distension: May indicate internal bleeding, bladder rupture, or severe infection

What to Do Before the Vet Visit

If you notice blood in your dog's urine and a vet visit is planned (but not an emergency):

• Collect a sample: Catch a midstream urine sample in a clean container. Keep it refrigerated and bring it to the appointment within a few hours
• Note the timing: Does the blood appear at the start, end, or throughout urination? This helps localise the source
• Document other symptoms: Increased frequency, straining, accidents, appetite changes, lethargy, or any other unusual behaviour
• Don't restrict water: Keep fresh water freely available — dehydration will worsen urinary problems

For a comprehensive overview of how to recognise discomfort in your pet, visit our resource on signs your pet is in pain. Early intervention can make a significant difference in outcomes, so when in doubt, call your vet.