title: Effect of penicillin or penicillin and dexamethasone in cattle with infectious bovine keratoconjunctivitis.
abstract: To evaluate the efficacy of penicillin or penicillin and dexamethasone for treatment of infectious bovine keratoconjunctivitis, 6- to 8-month-old beef heifers with clinical signs of infectious bovine keratoconjunctivitis were randomly assigned to 1 of 3 treatment groups: penicillin only, penicillin and dexamethasone, or control. Cattle assigned to the penicillin group (n = 18) were treated with 3 daily subconjunctival injections of procaine penicillin G. Cattle assigned to the penicillin/dexamethasone group (n = 13) were treated with 3 daily subconjunctival injections of procaine penicillin G and dexamethasone sodium phosphate. Control cattle (n = 14) were not treated. Healing times and frequency of recurrence for corneal ulcers; severity, diameter, and surface area measurements of corneal ulcers; and clinical scores did not differ among the 3 groups. Frequency of Moraxella bovis isolation from specimens of ocular secretions from ulcerated and non-ulcerated eyes was similar in all groups. Minimum inhibitory concentration of penicillin G for 95 of the 102 tested M bovis isolates was 0.3 U/ml, and for 7 others was 0.03 U/ml. When first and last specimens from 42 of 45 calves with isolation of M bovis on serial microbial cultures were compared, the susceptibility of each last isolate was similar to that of the corresponding first isolate.
authors.affiliation: Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis 95616, USA.
authors.forename: L J
authors.initials: LJ
authors.lastname: Allen
authors.forename: L W
authors.initials: LW
authors.lastname: George
authors.forename: N H
authors.initials: NH
authors.lastname: Willits
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy*; D003228:Conjunctiva; D003907:Dexamethasone / Q000008:administration & dosage / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D007267:Injections / Q000662:veterinary; D007639:Keratoconjunctivitis, Infectious / Q000188:drug therapy*; D016955:Moraxella bovis / Q000187:drug effects; D016870:Neisseriaceae Infections / Q000188:drug therapy / Q000662:veterinary*; D010402:Penicillin G Procaine / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D012008:Recurrence
chemical_list: D010402:Penicillin G Procaine; D003907:Dexamethasone