Clinical, histologic, and bacteriologic findings in dairy cows with digital dermatitis (footwarts) one month after topical treatment with lincomycin hydrochloride or oxytetracycline hydrochloride.
OBJECTIVE
To compare the effectiveness of lincomycin and oxytetracycline for treatment of digital dermatitis (DD) in dairy cows through gross visual examination, histologic evaluation, and bacteriologic evaluation.


METHODS
Randomized controlled clinical trial.


METHODS
25 cows with DD lesions from a commercial Holstein dairy herd.


METHODS
Cows with DD lesions were randomly assigned to 1 of 3 groups: topical treatment with 10 g of lincomycin hydrochloride (n = 11), topical treatment with 10 g of oxytetracycline hydrochloride (11), and no treatment (3) on days 1 and 2 (d1). Biopsy specimens were obtained for histologic examination from DD lesions prior to treatment and 28 or 31 days (d30) after treatment for histologic examination. Cows were clinically examined on d1, days 12 or 14 (d14), and d30.


RESULTS
No difference was evident in clinical responses to lincomycin and oxytetracycline, so data were pooled; at d30, 8 of 11 of lincomycin-treated lesions and 7 of 11 oxytetracycline-treated lesions appeared visually healed, respectively. Gross visual examination suggested 73% (16/22) of treated cows were healed at d14 and 68% (15/22) of treated cows were healed on d30. Of the 15 lesions that appeared healed on d30, 7 of 15 were classified histologically as active (ulceration and bacterial invasion; 2/15) or incipient (5/15).


CONCLUSIONS
Clinical responses to lincomycin and oxytetracycline did not differ. Agreement was good between gross visual and histologic assessments of DD lesions before treatment; agreement 1 month after treatment was variable. Histologic evaluation could not distinguish incomplete healing from lesion recurrence.
Berry
Steven L
SL
Department of Animal Science, College of Agricultural and Environmental Sciences, University of California-Davis, Davis, CA 95616, USA. slberry@ucdavis.edu
Read
Deryck H
DH
Walker
Richard L
RL
Famula
Thomas R
TR
D000287:Administration, Topical; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy*; D003612:Dairying; D003872:Dermatitis / Q000188:drug therapy / Q000662:veterinary*; D005260:Female; D005533:Foot Dermatoses / Q000188:drug therapy / Q000662:veterinary*; D006724:Hoof and Claw; D008034:Lincomycin / Q000008:administration & dosage / Q000627:therapeutic use*; D010118:Oxytetracycline / Q000008:administration & dosage / Q000627:therapeutic use*; D010212:Papilloma / Q000188:drug therapy / Q000662:veterinary
D000900:Anti-Bacterial Agents; D008034:Lincomycin; D010118:Oxytetracycline