Introduction

Urinary tract infections (UTIs) are fairly common in domestic dogs, especially in females. UTIs are almost always painful. However, many affected dogs have a high pain threshold and show no outward signs of discomfort.

Symptoms of Urinary Tract Infection in Dogs

When a dog does have observable symptoms of a UTI, its owner may notice one or more of the following:

• Abnormally frequent urination (pollakiuria)
• Formation and passage of a large volume of urine (polyuria)
• Increased thirst/water intake (polydipsia)
• Straining to urinate or excessive urgency (stranguria)
• Difficulty urinating (dysuria)
• Inappropriate urination in places that are not customary (house, car, elsewhere)
• Incontinence
• Cloudy urine
• Malodorous urine (abnormal smell)
• Visible blood in the urine (hematuria)
• Lethargy; listlessness
• Depression
• Loss of appetite (inappetence; anorexia)
• Fever (elevated body temperature; pyrexia)
• Inflammation and irritation around the external genitalia
• Licking of the vulva (females)
• Vaginal discharge (females)

One of the most important things to remember about canine urinary tract infections is that regardless of the underlying cause, affected dogs often show no clinical signs. Even uncomplicated asymptomatic UTIs, if left untreated, can lead to a number of much more serious conditions, including kidney infection and septicemia.

Dogs at Increased Risk

Females are more likely to develop UTIs than are males. Dogs with underlying urinary disease, such as stones (uroliths; calculi) in the bladder or elsewhere in the urinary tract, congenital or acquired anatomical defects or cancer (neoplasia), are predisposed to developing lower urinary tract infections. Dogs with diseases that tend to cause production of abnormally dilute urine, such as hyperadenocorticism (Cushing’s disease) and diabetes mellitus, are at increased risk. Long-term administration of corticosteroids or other immunosuppressive medications, and systemic diseases that suppress the immune system, can also predispose dogs to lower urinary tract disease.