Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: Interstitial (idiopathic) cystitis, bladder inflammation with no identifiable cause, is well known in cats and people but uncommon in dogs. When a dog strains, urinates often, has accidents, or has blood in the urine, the cause is usually a bacterial urinary tract infection, bladder stones, or, in older dogs, a bladder tumor. A urine test is the key first step. Call your vet the same day if your dog is straining but producing little or no urine, which can be an emergency.
Signs of bladder inflammation
- Peeing small amounts often, or urgency
- Straining to urinate
- Blood in the urine
- Accidents in the house
- Licking the genital area
- Strong-smelling urine
Emergency signs
Go to a vet immediately if your dog is straining with little or no urine coming out, is vomiting, has a painful belly, or is lethargic. A blocked urethra, most often from stones in male dogs, is life-threatening.
Common causes
- Bacterial urinary tract infection (UTI): the most common cause, especially in female dogs.
- Bladder stones: such as struvite or calcium oxalate. Some breeds are prone to specific types.
- Bladder tumors: transitional cell carcinoma (urothelial carcinoma) is most common in older dogs, with Scottish Terriers and some other breeds at higher risk.
- Polypoid cystitis: benign growths in the bladder wall, often linked to long-term infection or stones.
- Medications: for example, cyclophosphamide chemotherapy.
- Idiopathic cystitis: considered only after other causes are ruled out.
How vets diagnose it
- Urinalysis to check for blood, crystals, and bacteria
- Urine culture, ideally from a sample collected with a needle directly from the bladder (cystocentesis)
- X-rays and ultrasound to look for stones, tumors, and bladder wall changes
- Bloodwork to look for conditions like diabetes, Cushing’s disease, or kidney disease that raise UTI risk
Treatment
- Bacterial UTI: antibiotics chosen based on culture. Current guidelines use short courses for simple infections in otherwise healthy dogs.
- Stones: some struvite stones can be dissolved with a prescription diet. Others need removal by surgery or less invasive procedures.
- Tumors: anti-inflammatory medication and chemotherapy, sometimes other procedures.
- Idiopathic cystitis: pain relief, more water intake, and addressing stress.
Home care that helps
- Encourage drinking: fresh water in several places, water added to food, or wet food.
- Frequent bathroom breaks so urine doesn’t sit in the bladder.
- Follow any prescribed diet strictly if your dog has stones.
- Keep the genital area clean, especially in dogs with skin folds around the vulva.
- Healthy weight.
What to avoid
- Cranberry as treatment: cranberry products haven’t been shown to treat UTIs in dogs, though some vets use them for prevention.
- Apple cider vinegar: no evidence it helps, and it can upset the stomach.
- Human urinary pain relievers such as phenazopyridine (AZO), which can harm pets.
- Leftover antibiotics, which can mask the problem and encourage resistant bacteria.
- Restricting water to reduce accidents.
Frequently asked questions
Do dogs get interstitial cystitis like cats?
It’s much less common in dogs. Most dogs with bladder signs have an infection, stones, or another identifiable cause.
Why does my dog keep getting UTIs?
Recurrent infections usually have an underlying reason, such as stones, anatomy, diabetes, Cushing’s disease, or a tumor. Ask your vet about further testing.
Can stress cause bladder problems in dogs?
Stress can cause house soiling and marking, but it’s rarely the sole cause of bladder inflammation in dogs. Rule out medical causes first.
Sources
- Weese JS, et al. International Society for Companion Animal Infectious Diseases (ISCAID) guidelines for the diagnosis and management of bacterial urinary tract infections in dogs and cats. Vet J. 2019
- Lulich JP, et al. ACVIM small animal consensus recommendations on the treatment and prevention of uroliths in dogs and cats. J Vet Intern Med. 2016
- Merck Veterinary Manual: Noninfectious diseases of the urinary system in small animals
- Merck Veterinary Manual: Bacterial cystitis in small animals
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.