In growing pigs, chlortetracycline induces a reversible green bone discoloration and a persistent increase of bone mineral density dependent of dosing regimen.
We studied in growing pigs the effects of exposure to dietary chlortetracycline on bone mineral density (BMD) and bone color. Pigs were randomly allocated to a drug-free diet (n=48) or a diet fortified with 800 ppm of chlortetracycline, starting either at 28- or 84-d of age, and for either a 28- or 56-d duration (n=16 pigs/group). The lumbar vertebral discoloration and BMD of randomly chosen pigs were evaluated at 28-d intervals up to 168-d of age. The odds of bone discoloration increased with dosing duration and age at treatment onset, and decreased with the withdrawal time and age at treatment onset interaction (p < or = 0.001). The measured trabecular BMD linearly increased with age and squared treatment duration (p < or = 0.005). Therefore, TC-induced bone discoloration is reversible, and may be prevented with proper dosing regimen design. Moreover, TC induces a persistent increase on BMD that could be detected with quantitative computed tomography.
Guillot
Martin
M
Groupe de Recherche en Pharmacologie Animale du Québec, Centre de Recherche en Infectiologie Porcine (CRIP), Department of Veterinary Biomedical Sciences, Faculté de Médecine Vétérinaire, Université de Montréal, C.P. 5000 Saint-Hyacinthe, Québec, Canada J2S 7C6.
Alexander
Kate
K
Pomar
Candido
C
Del Castillo
Jérôme R E
JR
D000818:Animals; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000494:pharmacology; D015519:Bone Density / Q000187:drug effects*; D001846:Bone Development / Q000187:drug effects; D001842:Bone and Bones / Q000187:drug effects*; D002751:Chlortetracycline / Q000009:adverse effects* / Q000494:pharmacology; D003116:Color; D004305:Dose-Response Relationship, Drug; D008159:Lumbar Vertebrae / Q000187:drug effects; D008297:Male; D013552:Swine / Q000254:growth & development
D000900:Anti-Bacterial Agents; D002751:Chlortetracycline