10 month old had 2 uti's , had symptoms for #3 in less 2 months.. on meds. culture neg, waiting to do tests could teething cause high white blood cells?

No: Teething does not cause an elevation of your white blood cell count. An elevated WBC count a this age is almost always due to an infection somewhere, and with a history of uti's already i would be looking in this area. It could be a kidney abcess, blood infection, or infection totally somewhere else in the body. There are other more rare causes of elevated wbc's, but teething is not one of them.

Likely false UTI's: Unless you obtain a quality specimen the label UTI is often overused. A bag urine from a little girl often contains a washout of debris from her vagina, including WBC's. Only a clean catch or cath urine should be considered adequate to diagnose a UTI. If the kid has truly had 3 valid UTI's under a year of age studies looking for kidney/ureter & bladder defects is needed.