Urinary Tract Infection (UTI)

Urinary tract infections occur when bacteria - most commonly E. coli - colonise the urethra and bladder. Female dogs are significantly more susceptible than males due to their shorter urethra. UTIs are common across all breeds, though dogs with diabetes mellitus, Cushing's disease, or recessed vulvas are at higher risk.

A single UTI that responds to treatment and doesn't recur is usually straightforward. Recurring UTIs - typically defined as three or more per year - warrant investigation to identify why the urinary tract is failing to clear infections naturally.

Signs to monitor

Classic UTI signs:

• Frequent urination - going out to urinate more often than usual, or appearing to need to go urgently
• Small volumes of urine each time
• Straining or pain during urination
• Blood in urine (haematuria) - may be visible as a pink or red discolouration
• Licking at the vulva or prepuce more than usual
• Accidents indoors in a house-trained dog

Signs of kidney involvement (pyelonephritis):

• All of the above plus fever, lethargy, and back or flank pain
• Pyelonephritis (kidney infection) is more serious than a simple bladder infection and requires prompt treatment

In male dogs: Straining to urinate with little or no output warrants emergency assessment - this may represent urethral obstruction rather than a simple UTI. See the urinary blockage emergency guidance below.

Daily monitoring for dogs with known UTI

Log daily:

• Number of urination attempts
• Estimated urine volume each time
• Presence of blood (colour and amount)
• Whether the dog is straining
• Appetite and demeanour
• Medication given (antibiotic name, dose, time)

Continue logging for one week after completing the antibiotic course - signs that return within days of finishing treatment suggest the infection wasn't fully cleared.

Diagnosis

A urine sample is essential for diagnosis and for guiding antibiotic choice. Options for collection:

• Cystocentesis: The vet collects urine directly from the bladder with a needle - the most reliable sample for culture, avoiding contamination
• Free-catch (midstream): A clean catch collected at home - adequate for dipstick testing and cytology, but contamination can mislead culture results

A urine culture and sensitivity test identifies the specific bacteria and the antibiotics it is sensitive to. This is more useful than empirical (guess) antibiotic selection, particularly for recurring infections.

Antibiotic treatment

Most UTIs respond within 3–7 days of appropriate antibiotics, with the recommended course typically being 7–14 days. Ensure the full course is completed even if signs resolve earlier - premature cessation leaves surviving bacteria and increases resistance risk.

For recurring UTIs, a post-treatment culture 7–10 days after completing antibiotics confirms the infection has cleared.

Investigating recurring UTIs

If your dog has three or more UTIs per year, investigation for an underlying cause is worthwhile:

• Anatomical factors: Recessed vulva, urethral abnormalities, vaginal conformation issues
• Metabolic conditions: Diabetes mellitus, Cushing's disease (both suppress immune function and create environments favouring bacterial growth)
• Urinary stones: Stones in the bladder create a nidus for bacterial colonisation
• Immunosuppression: Dogs on long-term steroids
• Incomplete bladder emptying: Neurological causes, anatomical causes

When to contact your vet

Contact your vet urgently if:

• A male dog is straining to urinate with little or no urine output - this may be an obstruction
• Signs of kidney infection (fever, flank pain, lethargy with urinary signs)

Contact your vet promptly if:

• Blood in urine
• Straining and frequent small urinations without recent UTI diagnosis

Schedule a routine appointment for:

• A post-treatment culture to confirm clearance
• Investigation of recurring infections

Frequently Asked Questions

Can I treat a dog UTI with home remedies? No home remedy has sufficient evidence to treat a bacterial UTI. Cranberry preparations are often suggested but the evidence in dogs is weak, and cranberry does not clear an established infection. Antibiotics are required.

My dog keeps getting UTIs. What can I do? Recurrent UTIs warrant a vet investigation to find the underlying cause - this changes the management significantly. Ensuring the dog empties the bladder fully when urinating (some dogs go frequently in small amounts but don't fully empty), managing any predisposing conditions, and sometimes low-dose prophylactic antibiotics are options depending on the cause.

Is blood in urine always a UTI? No. Haematuria (blood in urine) can also result from bladder stones, bladder tumours, kidney disease, and clotting disorders. A UTI is the most common cause, but a vet should assess any blood in urine, particularly if it recurs or if other signs are absent.

My dog was treated for a UTI but still seems uncomfortable. What now? Contact your vet. The antibiotic may not have been the right one for the bacterial strain, the course may have been too short, or there may be an underlying cause that hasn't been addressed. A repeat urine culture can clarify whether infection persists.

Can male dogs get UTIs? Yes, though much less commonly than females due to the longer urethra. In male dogs, UTIs may indicate prostate disease in intact males, or anatomical abnormalities. Any urinary signs in a male dog warrant prompt veterinary assessment.