Antibiotic residues in milk samples obtained from cows after treatment for papillomatous digital dermatitis.
OBJECTIVE
To determine whether there would be detectable antibiotic residues in milk obtained from dairy cattle with papillomatous digital dermatitis (PDD) after topical treatment with oxytetracycline.


METHODS
Randomized controlled clinical trial.


METHODS
28 lactating Holstein cows with PDD.


METHODS
Cows were assigned to 2 treatment groups. Treatment 1 (n = 16) consisted of spraying of PDD lesions with 15 ml of a solution containing 100 mg of oxytetracycline/ml; lesions were sprayed twice daily for 7 days, using a garden sprayer. Treatment 2 (n = 12) consisted of a one-time application of a bandage that consisted of cotton soaked with 20 ml of a solution containing 100 mg of oxytetracycline/ml. Milk samples were obtained before and after treatment and assayed for tetracycline content by use of high-performance liquid chromatography and a commercially available tetracycline screening test.


RESULTS
None of the cows in either treatment group had violative residues of oxytetracycline in milk samples.


CONCLUSIONS
Producers treating lactating cows that have PDD, via topical application of oxytetracycline solution at the concentrations reported in this study, have a low risk of causing violative antibiotic residues in milk.
Britt
J S
JS
Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706-1102, USA.
Carson
M C
MC
von Bredow
J D
JD
Condon
R J
RJ
D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000627:therapeutic use; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy*; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D003872:Dermatitis / Q000188:drug therapy / Q000662:veterinary*; D004350:Drug Residues / Q000032:analysis*; D005260:Female; D005534:Foot Diseases / Q000188:drug therapy / Q000662:veterinary*; D006724:Hoof and Claw; D008892:Milk / Q000737:chemistry*; D010118:Oxytetracycline / Q000032:analysis / Q000627:therapeutic use; D010212:Papilloma / Q000188:drug therapy / Q000662:veterinary*; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D010118:Oxytetracycline