Oxytetracycline concentrations in healthy and diseased calves
Ames, T.R.; Larson, V.L.; Stowe, C.M.
American Journal of Veterinary Research 44(7): 1354-1357
1983
ISSN/ISBN: 0002-9645 PMID: 6881673 Document Number: 209705
Pneumonia was induced (by cold stress followed by bovine diarrhoea virus and Pasteurella multocida infection) in a group of calves that were then treated with one intravenous injection of oxytetracycline (OTC) 11 mg/kg Plasma pharmacokinetics and tissue concentrations differed from those of healthy controls. The volume of distribution and the half-life of OTC were increased in the group with pneumonia. Tissue concentrations of OTC (1.48 plus or minus 0.29 mu g/ml) were greater in the lungs of calves with pneumonia than that in the lungs (1.09 plus or minus 0.09 mu g/ml) of healthy controls. For the dose of OTC used, the correlation between serum concentration and tissue concentrations at 24 hours was poor. Antibiotic dosages and dosage intervals may prove inadequate if they are based solely on blood and tissue values of healthy animals.