Post-therapy antibody titers in dogs with ehrlichiosis: follow-up study on 68 patients treated primarily with tetracycline and/or doxycycline.
The clinical and serological responses to therapy were evaluated for at least 1 year in 68 dogs with antibody titers positive for Ehrlichia canis. Treatments were of variable periods with primarily tetracycline hydorchloride and/or doxycycline. Sixteen dogs had initial titers of 1:20 and, at the end of the year, were asymptomatic, no longer receiving medication, and had negative serology. The average length of treatment with tetracycline HCl and/or doxycycline was 85 days (range, 14 to 360 days). Of 39 dogs with initial titers of 1:2,560 or greater, 1 died, 25 were asymptomatic, and 13 were lost to follow-up at the end of the study. The average length of treatment was 210 days (range, 21 to 630 days). Twenty-seven dogs were seropositive at > or = 1:2,560 when the sera was last tested. Thirteen dogs had initial titers of 1:80 to 1:1,280. Of these 13 dogs, 2 died, 2 were lost to follow-up, and 9 were asymptomatic and had titers ranging from negative to > or = 1:2,560 at the end of the study. The persistence of antibodies, prolonged subclinical phase, and delayed relapses despite long-term medication, suggest inadequate chemotherapeutic agents or may be natural features of latency of ehrlichiosis in dogs.
Bartsch
R C
RC
Department of Pathology, Southwest Veterinary Diagnostics, Inc., Phoenix, AZ 85022, USA.
Greene
R T
RT
D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D000907:Antibodies, Bacterial / Q000097:blood*; D004283:Dog Diseases; D004285:Dogs; D004318:Doxycycline / Q000627:therapeutic use*; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D016873:Ehrlichiosis / Q000188:drug therapy / Q000276:immunology / Q000662:veterinary*; D019084:Fluorescent Antibody Technique, Indirect; D005500:Follow-Up Studies; D013752:Tetracycline / Q000627:therapeutic use*; D013997:Time Factors
D000900:Anti-Bacterial Agents; D000907:Antibodies, Bacterial; D013752:Tetracycline; D004318:Doxycycline