Collecting a Urine Sample, When & Why “pee into the cup” doesn’t work

Urinary tract infections are quite common in dogs and cats. An important aspect of managing urinary tract infections (UTIs) is getting a proper diagnosis. Diagnosing a UTI involves a few different things:

Clinical signs: Does your pet have signs that indicate something abnormal is going on in the bladder? This can include frequent urination, abnormal urination, straining to urinate or similar problems.

Cytological: When a urine sample is examined under the microscope, are there changes consistent with an active infection, like the presence of large numbers of white blood cells and red blood cells?
Culture: Can bacteria be grown from the urine sample?

Culture is very important to help determine if a UTI is really present. It’s also very important for determining the best treatment, especially since antibiotic resistant bacteria are becoming more common. A baseline culture is also useful if the infection comes back, as it provides information about whether the first bug was not actually eliminated or whether re-infection other bacteria has occurred. Differentiating these two situations is important for determining subsequent treatment as well as the need for additional testing to see if there are any underlying reasons for recurrent infections.

Culture is also something that can be done improperly. If a person has or may have a UTI, that person will usually be asked to collect your own “mid-stream” urine sample by collecting urine into a sterile cup part-way through urination, so that any superficial bacterial contaminants get flush out before the sample is collected. That’s not so easy to do in dogs and cats. Collecting midstream free-flow samples into a sterile container without the sample being contaminated by the pets hind end or haircoat, or by the person doing the collecting, is very difficult. A contaminated sample can result in misleading conclusions and potentially inappropriate treatment. Getting a proper sample is critical.

Cystocentesis Procedure:

Cat getting an ultrasound guided cystocentesis

Typically it is a very quick, simple and low risk procedure that involves taking a sample directly out of the bladder using a needle and syringe (video below).  Nevertheless, it is important that this procedure is done in a safe and clean manner by an experienced veterinarian as the risks can be high – as you might guess having a long needle among vital and sensitive organs! Thus, a calm, quiet, & low stress environment is important.  The pet is placed on it’s back (no anesthesia required, and usually even sedation is unnecessary), the skin is cleaned, and a thin needle is passed through the lower part of the belly, where the bladder lies directly under the skin, similar to an amniocentesis during pregnancy, and urine is drawn out with a syringe. In difficult cases where the bladder is very small, abnormal or is anatomically abnormal imaging is helpful and an ultrasound can be used during the procedure.

While cystocentesis may seem like a big deal for collection of a fluid that the pet passes freely on a regular basis, it provides much better information and is largely considered the standard for urine collection in dogs and cats. Unless there is a medical reason not to do it, cystocentesis should be used for collection of urine samples for culture.

We hope this information is useful, of course, if you have any questions at all let any of our friendly staff members or myself know.

Dr. Childs




Good demo of a cystocentesis, it is a very similar procedure in dogs and cats.

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