Use of enrofloxacin for treatment of large-form Haemobartonella felis in experimentally infected cats.
OBJECTIVE
To compare treatment with enrofloxacin and doxycycline with no treatment in cats experimentally infected with Haemobartonella felis.


METHODS
Prospective case-control study.


METHODS
16 cats.


METHODS
Cats were inoculated with large-form H. felis from a chronically infected donor. Cats were assigned to 1 of 4 treatment groups: doxycycline (5 mg/kg [2.3 mg/lb], p.o., q 12 h), low-dose enrofloxacin (5 mg/kg, p.o., q 24 h), high-dose enrofloxacin (10 mg/kg [4.5 mg/lb], p.o., q 24 h), and an untreated control group. Clinical signs, Hct, blood smears, and a polymerase chain reaction (PCR) assay were used to monitor progression of the infection.


RESULTS
All cats were confirmed to be infected with H. felis via blood smear evaluations and PCR assay results. Treatment had no effect on Hct during the intratreatment period, but Hct values were significantly greater in the low-dose enrofloxacin group, compared with the control group, during the posttreatment period. During the intratreatment period, H. felis organism counts per 1,000 RBC in the doxycycline treatment and the high-dose enrofloxacin treatment groups decreased at a significantly faster rate than those in the control group. In the posttreatment period, organism counts in the doxycycline treatment group and the low- and high-dose enrofloxacin groups decreased at significantly faster rates than counts in the control group. There was no significant effect of treatment on the number of positive PCR assay results. Two cats treated with enrofloxacin and 1 cat treated with doxycycline completely cleared the H. fe is organism despite presumed immunosuppression caused by glucocorticoids.


CONCLUSIONS
Results support the hypothesis that enrofloxacin has anti-H. felis effects.
Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA.
Kristy L
KL
Dowers
Christine
C
Olver
Steven V
SV
Radecki
Michael R
MR
Lappin
D000710:Anaplasmataceae / Q000235:genetics; D000711:Anaplasmataceae Infections / Q000188:drug therapy / Q000662:veterinary*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D016022:Case-Control Studies; D002371:Cat Diseases / Q000188:drug therapy* / Q000382:microbiology; D002415:Cats; D018450:Disease Progression; D004305:Dose-Response Relationship, Drug; D004318:Doxycycline / Q000627:therapeutic use*; D000077422:Enrofloxacin; D005260:Female; D024841:Fluoroquinolones; D006400:Hematocrit / Q000662:veterinary; D008297:Male; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011446:Prospective Studies; D015363:Quinolones / Q000627:therapeutic use*; D011897:Random Allocation; D013047:Specific Pathogen-Free Organisms; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D015363:Quinolones; D000077422:Enrofloxacin; D004318:Doxycycline