UTI Question - Urinalysis Positive/Culture Negative

Hi Everyone,

My Jill is six weeks post her chemotherapy treatment for osteosarcoma (bone cancer) and has been doing wonderful - no side effects throughout the entire treatment, with the exception of low white blood cells after two sessions.

On Thursday of last week, I woke up to find her asleep in a pool of her own urine, soaking wet.  She has never in her 8 years peed outside the litter box.  Her oncologist had me take her to her general vet for a urinalysis and culture as she suspected a UTI, which kitties on chemo are prone to due to a lowered immune system.

The urinalysis showed signs of a UTI - Bacteria ("rare rods"), RBC's and WBC's and some Protein.  So we started her on clavamox while we waited for the culture to come back. 

Two nights ago, she was vomiting perfusely for three hours straight, so I called the vet in the morning (knowing this was most likely due to the clavamox).  The vet called the lab for an update on the culture and so far the culture is coming back negative for any signs of a UTI.  So for now, we are stopping the antibiotics all together.

My question for you all is this, have any of you experienced your kitty having a UTI before where the urinalysis came back positive, and the culture negative?  The urinalysis sure does look like it's a UTI and I don't want her her Antibiotics completely if it is indeed a UTI as I want to nip this in the bud right away since her immune system in compromised.

Thanks for any information you can provide!!!!

Erica & Tripawd Kitty Jill

It can depend on how the urine samples were obtained.  A free catch urine sample can often have bacteria present simply from coming out the cat's back-side. So, usually you can't rely on bacterial analysis from a free catch. A sample taken with a sterile needle (via cystocentesis) won't have any external bacteria in there, so that's the recommended procedure for a culture & sensitivity test. This sample is sterile, except for whatever is inside the bladder, so you can rely on the bacterial analysis here. If the sample used for both tests came from the same method of collection, I'm not sure what's going on.

The other thing to note is that it is generally better to wait for the culture to identify the specific bacteria before antibiotics are given, so that you can be sure it's the correct antibiotic for that bacteria. A lot of time, vets don't wait (or don't do a culture), and a broad-spectrum antibiotic is given. While that works in a lot of cases, in the ones that don't, it sometimes creates more problems.
 

Thanks for your reply!  The sample was taken via  cystocentesis for both the urinalysis and culture/sensitivity.  I should note, the culture is not complete yet, these were preliminary results we got yesterday (sample was taken on Thursday).

It would be unusual to get a false positive from a sample taken via cystocentesis. At this point, given Jill's probable reaction to the Clavamox, I would wait for the culture results and give only the antibiotics she needs for that specific bacteria. Cultures usually take 3-5 days so you should know something soon.