Recently one of our readers asked me to chat about how urinary tract infections (UTIs) can affect diabetes. She said that her senior kitty’s diabetes management kept getting derailed by his urinary tract infections. This reminded me of the brain teaser, “Which came first, the chicken or the egg?” Let me explain.

Uncontrolled diabetes results in a high blood glucose reading for at least part of the day. When the blood glucose is elevated, sugar spills over into the urine, pulling extra fluid along with it. Sugary, dilute urine is very inviting for bacteria. Compare this to concentrated urine without sugar, which is an unpleasant place for bacteria to reside. Uncontrolled diabetics are predisposed to urinary tract infections.

Remember also that infection of any kind is a trigger to insulin resistance, whether it is insulin that a pet makes on its own or insulin that we give via injection. One of the more common sites of infection in middle aged and older pets is oral infection. Perhaps the second most common source of infection in diabetic pets (for reason already mentioned) is urinary tract infection.

Now, how do we determine if there is a urinary tract infection? Your pet is diabetic, you already expect your pet to go potty more frequently than he or she did prior to having diabetes. Pets with urinary tract infections also go potty more frequently than usual. The typical urinary tract infection presents with frequent straining and increased urge to urinate. Your pet may not make it until you get home from work or will ask to go outside more often than usual. If your pet is diabetic, the clear cut symptoms of increased urinations may be less obvious.

If we suspect a UTI, we run a urinalysis. However, a diabetic tends to be immunosuppressed and may not mount the same response to a bladder infection as a non-diabetic pet. If we run a urinalysis, the results we find in a classic UTI (lots of red blood cells, bacteria and white blood cells) may be more subtle due to the sheer dilution of the urine in a diabetic and the decreased response from diabetic immunosuppression. This is why most veterinarians recommend urinalysis with a urine culture (about twice yearly) for diabetic pets.

So, our reader who recognized that her sweetie’s diabetic control deteriorated when he had a urinary tract infection is a smart cookie.

However, unregulated diabetes can also result in the urinary tract infection. It’s that chicken and the egg dilemma. As you see, it really is important to monitor urinalyses and urine cultures, and not just the blood glucose when we have a diabetic pet.


NOTE: Consult your veterinarian to confirm that my recommendations are applicable for the health needs of your pet.

Dr . Joi Sutton

Dr . Joi Sutton

Dr. Joi Sutton is a 1993 graduate from Oregon State University. She has practiced both in emergency medicine and general practice. Dr. Sutton has done extensive international volunteer work and is the President and Founder of Veterinary Ventures, a nonprofit organization that takes teams of veterinarians to undeveloped countries for humane medical care. She also runs a small animal practice in South Florida.
Dr . Joi Sutton