Bacterial urinary tract infection
Also called Bacterial cystitis, UTI
Bacteria that climb into the bladder cause frequent, painful or bloody urination. Female dogs and cats, and cats over 10 years, are at higher risk. Treating without the right antibiotic can lead to resistance.
Cause and spread
- Cause
- Mostly gram-negative bacteria, usually Escherichia coli, rising from the skin around the genitals.
- How it spreads
- It is not usually spread between animals. Risk is higher with incomplete bladder emptying, dilute urine, sugar in the urine (diabetes) and weakened immunity.
Signs to watch for
- Frequent small urinations
- Straining or pain when urinating
- Blood in the urine
- Urinating in the wrong places
- Leaking urine
Many diseases look alike. Only a laboratory test can tell them apart, so please see a veterinarian for any sick animal.
How it is diagnosed
A urinalysis with a microscope check of the urine sediment is the minimum. A urine culture and sensitivity test is recommended to name the bacteria and pick the antibiotic. The number of bacteria matters, and the way the urine was collected changes how results are read.
- Usually the first testUrinalysis (Complete)Checks the urine and its sediment.
- Usually the first testUrine Sediment MicroscopyLooks for bacteria, white cells and blood.
- Confirms the diseaseBacterial Culture and Sensitivity (panel)Grows the bacteria and shows which antibiotics work.
- Supports the diagnosisUrine Dipstick (Chemical)A quick chemical check.
Prevention and control
- Allow frequent chances to urinate and fresh water at all times
- Treat underlying problems such as diabetes or kidney disease
- Complete the course of antibiotics your veterinarian prescribes, chosen from a sensitivity test
Where this information comes from
- Bacterial Cystitis in Small Animals · Merck Veterinary Manual
General information for animal owners and veterinarians, last checked October 2026. It does not replace the advice of your veterinarian, who should decide which tests and treatment your animal needs.