title: Milk and serum concentration of ceftiofur following intramammary infusion in goats.
abstract: Five dairy goats were used to determine the milk and serum concentrations along with elimination characteristics of ceftiofur following intramammary administration. One udder half of each goat was infused twice with 125 mg ceftiofur with a 24-h interval between infusions. Milk samples were collected at 1, 2, 8, and 12 h after the last infusion and then every 12 h for a total of 7 days. Blood was collected from each animal at 3, 8, 12, and 24 h after infusion and then every 24 h for 6 days. Following a washout period of 1 week, the experiment was repeated using the opposite udder half. The elimination half-life of ceftiofur from the mammary gland was 4.7 h. The concentration of ceftiofur was greater than published MIC90 values for Staphylococcus spp. bacteria for 24 h. Ceftiofur was absorbed into systemic circulation from the mammary gland. The maximum concentration was 552 ng/mL at 3 h after infusion, and the serum elimination half-life was 10 h. Intramammary infusion of 125 mg ceftiofur every 24 h can be expected to maintain drug concentration in milk above published MIC90 for Staphylococcus spp.
authors.affiliation: Department of Veterinary Clinical Medicine, University of Illinois, Urbana, IL, USA.
authors.forename: E F
authors.initials: EF
authors.lastname: Garrett
authors.affiliation: Department of Comparative Biosciences, University of Illinois, Urbana, IL, USA.
authors.forename: L
authors.initials: L
authors.lastname: Dirikolu
authors.affiliation: Veterinary Medicine Research & Development, Zoetis Inc., Kalamazoo, MI, USA.
authors.forename: G S
authors.initials: GS
authors.lastname: Grover
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics*; D002511:Cephalosporins / Q000008:administration & dosage / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics*; D004333:Drug Administration Routes / Q000662:veterinary; D005260:Female; D015511:Goat Diseases / Q000188:drug therapy; D006041:Goats / Q000378:metabolism; D008321:Mammary Glands, Animal; D008413:Mastitis / Q000188:drug therapy / Q000662:veterinary; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D008892:Milk / Q000737:chemistry*; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000662:veterinary
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; C053503:ceftiofur