Antibiotics for Urinary Tract Infection in Cats

By Missy Zane

Urinary tract infections in cats under age 10 are often not infections at all, but rather painful collections of tiny stones or crystals that irritate the walls of the bladder, causing discomfort and pain. In male cats, they can be very dangerous and even fatal. While antibiotics won't get rid of stones or crystals, they can make the cat more comfortable by reducing inflammation and preventing secondary infections.


Convenia is a broad spectrum antibiotic that treats a wide range of bacterial infections. According to the manufacturer, Phizer Animal Health, one injection provides an assured course of treatment for 14 days. The most common side effects include lethargy, anorexia, diarrhea and vomiting.


Amoxicillin is also a broad spectrum antibiotic. The most common side effects are vomiting and diarrhea. Giving a probiotic such as FortiFlora while your cat is on amoxicillin can prevent stomach upset. Most veterinarians sell FortiFlora.


Clavamox is a combination of amoxicillin and clavulanate, and is used to treat bacteria that is resistant to amoxicillin alone. The most common side effect is diarrhea, although some cats may vomit soon after taking the medicine. A probiotic will restore the intestinal flora destroyed by Clavamox and will help with stomach upset.


Another broad spectrum antibiotic, Baytril's most common side effect is diarrhea. However, injectable Baytril has caused blindness in some cats. In young animals, it can damage the cartilage of the joints.


This broad spectrum antibiotic is available as a film-covered tablet that is easy for cats to swallow. Do not use Zeniquin in cats under 12 months of age. This drug may affect a cat's retina. Other, more common side effects include loss of appetite, vomiting, diarrhea, drowsiness and dizziness.

Beyond Medication

Diet plays an important part in preventing urinary tract infections (UTIs) and Feline Lower Urinary Tract Disease. Cats who are prone to UTIs do best on an all-wet food diet, which keeps them well hydrated, and creates dilute urine and an environment that is inhospitable to the formation of crystals and stones.