Foul-smelling urine in dogs can be a result of bacteria in the urinary tract or from ketones in the urine caused by diabetes, explains the Whole Dog Journal. Bacterial infections can inhabit the bladder to cause lower urinary tract infections, or the kidneys to cause upper urinary tract infections, notes PetMD.
Lower urinary tract infections can occur in dogs of any gender or age. However, older dogs have an increased risk of developing infections, as do female dogs. Other signs associated with bladder infections include frequent urination, difficulty urinating, leaking urine and the presence of blood in the urine. While infections can be the result of several different types of bacteria, most dogs recover well with antibiotics.
When bacteria from a lower urinary tract infection travel up to the kidneys, they can cause a kidney infection, PetMD reports. The signs are similar to a bladder infection but may include a fever and lower back or abdominal pain. Untreated kidney infections may lead to a life-threatening blockage or sepsis. Veterinarians can also treat kidney infections with antibiotics.
Vets can detect ketones in the urine through a urinalysis, according to the Whole Dog Journal. A dog's body produces ketones while breaking down fatty acids for energy, and it can be a sign of under-nourishment. However, it is very common in dogs with diabetes. Ketones in the urine may give the urine a strong odor of nail-polish remover.
A routine urinalysis can detect many different ailments, the Whole Dog Journal explains. Any change to the odor, color or consistency of the urine is a sign to the owner that the dog should see a veterinarian.