Combined parenteral and oral administration of oxytetracycline for control of infectious bovine keratoconjunctivitis.
OBJECTIVE
To determine whether combined parenteral and oral administration of oxytetracycline would ameliorate a herd outbreak of infectious bovine keratoconjunctivitis (IBK) and to compare efficacy of this regimen with that of subconjunctival administration of procaine penicillin G.


METHODS
Randomized field trial.


METHODS
119 Hereford calves in a herd undergoing a naturally occurring outbreak of IBK.


METHODS
Calves were randomly assigned to 1 of the following 3 groups: oxytetracycline treatment, procaine penicillin G treatment, and control. After initial treatment, calves were examined 3 times/wk for 7 weeks. The surface area of all corneal ulcers was measured during each examination. Ocular secretions were collected from all calves at least weekly and were tested for Moraxella bovis.


RESULTS
Calves treated with oxytetracycline had a lower prevalence of IBK than did calves treated with procaine penicillin G or control calves and required fewer additional treatments than did calves treated with procaine penicillin G. Mean time for healing of corneal ulcers was significantly less for calves that received oxytetracycline or procaine penicillin G than for control calves. Calves treated with oxytetracycline developed fewer corneal ulcers and fewer recurrent ulcers than did calves in the other groups. Moraxella bovis was isolated less often from ocular secretions collected from calves in the oxytetracycline group than from calves in the other groups.


CONCLUSIONS
Combined parenteral and oral administration of oxytetracycline appears to be an effective method of reducing severity of a herd outbreak of IBK and may be superior to treatment of affected animals with procaine penicillin G.
Eastman
T G
TG
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis 95616-8734, USA.
George
L W
LW
Hird
D W
DW
Thurmond
M C
MC
D000284:Administration, Oral; D000287:Administration, Topical; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002140:California / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy* / Q000453:epidemiology; D003228:Conjunctiva; D004196:Disease Outbreaks / Q000662:veterinary; D007273:Injections, Intramuscular / Q000662:veterinary; D007639:Keratoconjunctivitis, Infectious / Q000188:drug therapy* / Q000453:epidemiology; D016955:Moraxella bovis / Q000302:isolation & purification*; D016870:Neisseriaceae Infections / Q000188:drug therapy / Q000453:epidemiology / Q000662:veterinary*; D010118:Oxytetracycline / Q000008:administration & dosage / Q000627:therapeutic use*; D010402:Penicillin G Procaine / Q000008:administration & dosage / Q000627:therapeutic use; D010406:Penicillins / Q000008:administration & dosage / Q000627:therapeutic use; D015995:Prevalence; D012008:Recurrence
D000900:Anti-Bacterial Agents; D010406:Penicillins; D010402:Penicillin G Procaine; D010118:Oxytetracycline