BLOOD IN URINE (HEMATURIA) IN DOGS/CATS
WHAT THIS SYMPTOM USUALLY MEANS
Blood in urine often indicates inflammation, infection, stones, or trauma somewhere along the urinary tract. In older dogs and cats, blood may also signal kidney disease or—less commonly—cancer. Any visible blood requires medical evaluation.
MOST COMMON CAUSES
MILD OR SELF-LIMITING CAUSES (COMMON)
• Mild cystitis
• Stress-related bladder inflammation (cats)
• Minor trauma from straining
• Post-exercise irritation (rare)
MEDICAL CAUSES THAT NEED DIAGNOSIS (MODERATE CONCERN)
• UTI
• Bladder stones or crystals
• Kidney infection
• Prostate disease (male dogs)
• Early kidney disease
• Sterile cystitis (cats)
EMERGENCY CAUSES (HIGH CONCERN)
• Urethral obstruction (especially male cats)
• Bladder rupture
• Acute kidney injury
• Blood clot obstruction
• Urinary tract cancer (older dogs)
RED FLAGS: WHEN THIS IS AN EMERGENCY
• Male cat with ANY blood in urine
• No urine produced + blood
• Vomiting, collapse, sudden lethargy
• Hard, painful abdomen
• Blood clots in urine
If you’re unsure, treat it as urgent.
AT-HOME CARE YOU CAN START NOW
• Encourage hydration
• Switch temporarily to 100% wet food
• Provide multiple clean litter boxes (cats)
• Avoid strenuous exercise
These steps do not replace a veterinary exam if symptoms continue or worsen.
WHAT A VETERINARIAN WILL CHECK
• Urinalysis (crystals, infection, blood cells)
• Urine culture
• X-rays to detect stones
• Ultrasound for bladder wall changes or masses
• Kidney bloodwork
• Prostate exam (male dogs)
MOST LIKELY DIAGNOSES (BASED ON 40 YEARS OF CASES)
• UTI
• Stones or crystals
• Feline idiopathic cystitis
• Kidney infection
• Prostatitis
• Urinary tract cancer (older dogs)
BREEDS OR AGES AT HIGHER RISK
• Senior dogs (TCC risk)
• Dalmatians, Bulldogs (stone formers)
• Older female dogs (UTIs)
• Male cats (risk of obstruction)
WHEN YOU SHOULD SCHEDULE A VETERINARY VISIT
Emergency: Male cats, blood with inability to urinate
Within 24 hours: Any visible blood in urine
Monitor: Very mild pink-tinged urine after known strenuous activity (rare)
EXPECTED RECOVERY TIME
• UTI: 3–5 days
• Stones: improves after removal
• FIC: 3–7 days
• Kidney infection: 1–2 weeks
• Cancer: varies widely
HOW THIS SYMPTOM RELATES TO LONGEVITY
Persistent inflammation or stones accelerate kidney damage—one of the top lifespanlimiting diseases in pets. Early detection improves long-term kidney health.
WHEN TO CONSIDER A LONGEVITY CONSULT
Recurrent blood in urine, stones, or early kidney disease are strong indicators to develop a long-term longevity plan.
FOR CANCER-RELATED CONCERNS
Blood with straining or chronic urinary symptoms in older dogs may indicate TCC (bladder cancer). Pet Cancer Navigator can help with diagnosis pathways and treatment options.
FAQ
Is a small amount of blood serious?
Yes—always evaluate.
Can stress cause bloody urine?
In cats, yes (FIC).
Can blood be from kidneys?
Yes—kidney infections are a major cause.