🦠 Vet Guide 2025: Urinary Tract Infections in Dogs and Cats – Causes, Diagnosis & Treatment 🐾💧

By Dr Duncan Houston, BVSc

💡 What Is a UTI in Pets?

A urinary tract infection (UTI) is an infection of the bladder, urethra, or other parts of the urinary system. In pets, most UTIs are bladder infections. Though common, UTIs can be painful and, if left untreated, may lead to kidney infection (pyelonephritis) or other complications. 🐶🐱

🩺 Common Signs of a Bladder Infection

• 🚽 Frequent urination in small amounts
• 💧 Inappropriate urination indoors
• 🩸 Blood-tinged urine
• 😿 Crying or straining while urinating
• 🌊 Increased thirst (sometimes)

In pets with chronic disease, weak immune systems, or bladder stones, signs may be subtle or absent—regular testing is critical.

🔬 Where Do UTIs Come From?

The bladder is normally sterile, but bacteria can ascend the urethra and colonize the bladder. Female dogs are more prone due to anatomy. UTIs are uncommon in young cats and neutered male dogs. 💥

🧪 Diagnosing a UTI

1. 🧫 Urinalysis

Checks for:

• ⚖️ Specific gravity (urine concentration)
• 🦠 White blood cells or bacteria
• 🧬 Protein, crystals, or pH changes

2. 🔬 Urine Culture & Sensitivity

The gold standard. Confirms whether bacteria are present and which antibiotics will work.

3. 🧪 Sample Collection Methods

• 💉 Cystocentesis: sterile sample from bladder via needle (best method)
• 🐕 Catheterization: sterile but less comfortable
• 🪣 Free catch: may be contaminated but useful for screening

💊 Treatment for Simple UTIs

• 💊 Antibiotics (3–14 days, depending on protocol)
• 📆 Recheck may include urinalysis or culture

Pets should improve within 48 hours. Always finish the full antibiotic course unless your vet says otherwise. 🔄

🔁 Recurrent UTIs – What to Check

A UTI is “recurrent” if:

• 🔁 3 or more infections in 12 months
• 🔁 2 or more infections in 6 months

Underlying Causes to Investigate:

• 🪨 Bladder stones
• 🎗️ Bladder tumors (e.g., transitional cell carcinoma)
• 💉 Kidney infection (pyelonephritis)
• 🔄 Urachal diverticulum (remnant of fetal bladder outflow)
• 💔 Prostatitis in intact male dogs
• ⚠️ Vaginal strictures (in females)

📸 When to Image the Bladder

• 🖥️ Ultrasound – best for tumors, stones, and diverticula
• 📸 X-rays – good for radiopaque stones
• 💧 Contrast studies – can highlight hard-to-see abnormalities

🔄 Post-Treatment Monitoring

• 📆 Culture 5–7 days after starting antibiotics (for complicated cases)
• 📅 Culture again 1 week post-treatment
• 🧪 Long-term checks at 1, 3, and 6 months for recurrence risk

🚫 What UTIs Are Not

Don't confuse UTIs with:

• 😼 Feline idiopathic cystitis (FIC): inflammatory, non-infectious, common in young cats
• ⚠️ Behavior issues (marking, housetraining lapses)
• 🧠 Canine cognitive dysfunction in seniors

🧪 UTI vs. FIC in Cats

FIC is not bacterial. It’s inflammatory, often triggered by stress, diet, and dehydration. Antibiotics do not help. If your cat is under age 10 and diagnosed with a UTI, ask whether it might be FIC instead. 🧠

🩺 Final Thoughts from Dr Duncan Houston

Urinary tract infections are common, painful, and very treatable. For most pets, a few days of antibiotics is all it takes. For pets with recurrent or complicated UTIs, further testing and imaging will help uncover the root cause. The earlier you act, the better the outcome. 🐾🩺

📲 Need UTI Help Today? Ask A Vet

Suspect a bladder infection? Not sure what tests your pet needs? Download the Ask A Vet app and chat 24/7 with Dr Duncan Houston and licensed veterinarians for real-time advice, second opinions, or test reviews 🐶🐱💬