title: Comparison of the efficacy of enrofloxacin, imidocarb, and oxytetracycline for clearance of persistent Anaplasma marginale infections in cattle.
abstract: This study compared enrofloxacin and imidocarb dipropionate treatments with an oxytetracycline regimen proposed by the World Organization for Animal Health for elimination of persistent Anaplasma marginale infections in cattle. The effect of therapy on competitive ELISA and polymerase chain reaction (PCR) reactivity was also assessed. Twelve A. marginale-infected carrier calves were randomly assigned to groups receiving either enrofloxacin (5 mg/kg IV q24h for 5 days), imidocarb (5 mg/kg IM twice, 7 days apart), or oxytetracycline (22 mg/kg IV q24h for 5 days). One calf infected with an Oklahoma isolate in the imidocarb group and one infected with a Virginia isolate in the oxytetracycline group failed to infect a splenectomized calf following blood subinoculation. Both became competitive ELISA negative by 44 days after treatment, but the imidocarb-treated calf remained PCR positive. None of the tested treatments reliably eliminated persistent A. marginale infections in all cattle. Furthermore, PCR was not a reliable means of determining the success of chemosterilization in calves.
authors.affiliation: Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 5001, USA.
authors.forename: Johann F
authors.initials: JF
authors.lastname: Coetzee
authors.forename: Michael D
authors.initials: MD
authors.lastname: Apley
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Kocan
mesh_terms: D042322:Anaplasma marginale / Q000187:drug effects; D000712:Anaplasmosis / Q000188:drug therapy*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000981:Antiprotozoal Agents / Q000008:administration & dosage / Q000494:pharmacology; D002353:Carrier State / Q000188:drug therapy / Q000662:veterinary; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy* / Q000382:microbiology; D000077422:Enrofloxacin; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D004912:Erythrocytes / Q000382:microbiology; D024841:Fluoroquinolones / Q000008:administration & dosage / Q000494:pharmacology*; D006400:Hematocrit / Q000662:veterinary; D007095:Imidocarb / Q000008:administration & dosage / Q000494:pharmacology*; D010118:Oxytetracycline / Q000008:administration & dosage / Q000494:pharmacology*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011897:Random Allocation; D013156:Splenectomy / Q000662:veterinary; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D000981:Antiprotozoal Agents; D024841:Fluoroquinolones; D000077422:Enrofloxacin; D007095:Imidocarb; D010118:Oxytetracycline