Farm- and host-level risk factors for papillomatous digital dermatitis in Chilean dairy cattle

A cross-sectional study was conducted in southern Chile between January and March, 1996, to identify risk factors for papillomatous digital dermatitis (PDD) in lactating daily and dual-purpose cows. A total of 3,265 cows from 22 farms were examined in the milking parlor for PDD lesions. Additional i nformation was collected from dairies' computerized records and by direct i nterview of managers. Data were analyzed using logistic and logistic-binomi al regression (with dairy as a random-effect term). German Red-Pied (dual-p urpose) cows were significantly (P < 0.05) less likely (odds ratio (OR) = 0 .3) to have PDD lesions than German Black-Pied and Holstein crossbreds. Fir st-parity cows had the highest odds of PDD, and odds diminished, in a dose- effect manner, as parity increased. Odds of PDD increased with increasing d ays in lactation. Cows that calved during winter were more likely to have P DD (OR = 1.4) than those calving at any other season. Cows on farms that bo ught heifers in the past 10 years had a 3-fold increase in the odds of PDD compared to those on farms that never bought heifers. Loose-housed cows had a higher risk of PDD (OR = 7), followed by cows in free stalls or in open corrals (OR = 2.8 and 1.3, respectively), compared to cows on pasture all y ear. Cows on dairies that used a footbath during 1996 were less likely (OR = 0.3) to have PDD than these in dairies not using one. Parlor type was ass ociated with PDD, but this was likely an effect of parlor design on ease of inspection of cows' feet. A policy of trimming all cows' vs. only lame cow s' feet and a policy about buying adult cows did not have significant effec ts on PDD risk. (C) 1999 Elsevier Science B.V. All rights reserved.