James L. Schaller, M.D.  •  239-263-0133

Florida and Carolina Pets Commonly Have Bartonella

I believe Bartonella is a fairly common infection that alters mood and behavior in some infected humans. Yet in psychiatric residencies and fellowships, and in infectious disease training, I do not believe Bartonella is given enough attention. I also do not think that most major lab corporations are set up to do a good job in testing for Bartonella.

In this study below they found more than half of the cats tested were positive for this infection. Unfortunately, veterinary physicians are often ahead of human medicine. This may be true with tick-borne infection science, and the quality of the lab tests used in tick-infection diagnosis.


Blood was collected from a convenience sample of 271 pet cats aged 3 months to 2 years (mean age, 8 months, median and mode, 6 months) between May 1997 and September 1998 in four areas of the United States (southern California, Florida, metropolitan Chicago, and metropolitan Washington, D.C.). Sixty-five (24%) cats had Bartonella henselae bacteremia, and 138 (51%) cats were seropositive for B. henselae. Regional prevalences for bacteremia and seropositivity were highest in Florida (33% and 67%, respectively) and California (28% and 62%, respectively) and lowest in the Washington, D.C. (12% and 28%, respectively) and Chicago (6% and 12%, respectively) areas. No cats bacteremic with B. clarridgeiae were found. The 16S rRNA type was determined for 49 B. henselae isolates. Fourteen of 49 cats (28.6%) were infected with 16S rRNA type I, 32 (65.3%) with 16S rRNA type II, and three (6.1%) were coinfected with 16S rRNA types I and II. Flea infestation was a significant risk factor for B. henselae bacteremia (odds ratio = 2.82, 95% confidence interval, 1.1 to 7.3). Cats >or=13 months old were significantly less likely to be bacteremic than cats <or=6 months old (odds ratio = 0.18, 95% confidence interval, 0.05 to 0.61). Flea infestation, adoption from a shelter or as a stray cat, hunting, and being from Florida or California were significant risk factors for B. henselae seropositivity. DNA fingerprint was significantly associated with region (P = 0.03) and indoor/outdoor status of cats (P = 0.03).

Guptill L, Wu CC, HogenEsch H, Slater LN, Glickman N, Dunham A, Syme H, Glickman L. Journal of Clinical Microbiology. Prevalence, risk factors, and genetic diversity of Bartonella henselae infections in pet cats in four regions of the United States. 2004;42:652-9.