I'm not sure if bart is like Lyme, as in if you treat early with abx being the most effective. But, if so, I don't think it would be a bad idea to have her treated if you can. Apparently, bartonella in cats is more endemic in warmer climates. Not the same as Lyme. In those climates, it is said it can be found in as high as 50% of cats.
Somebody said...
Some reports state that Bartonella has infected 12 percent to 50 percent or more of cats, but the risk of exposure varies greatly depending on the region of the United States. Areas with warmer climates have a higher incidence of fleas and, therefore, a higher percentage of cats infected with the disease.
http://www.vetstreet.com/care/bartonellosis-cat-scratch-disease