Risk factors for development of foot abscess in neonatal pigs.

Factors associated with foot abscess were evaluated in a cohort of 3,322 suckling pigs reared on a woven-wire floor (wire diameter, 0.5 cm; size of openings, 1 x 3.8 cm). In bivariate analysis, foot abscess was significantly (P < 0.05) associated with postpartum sow illness, number of pigs born alive, and parity, but not with birthweight (P = 0.31) or time spent on wire flooring (P = 0.89). One oxytetracycline treatment (100 mg, IM) at birth or 1 treatment at birth and a second 5 to 7 days later reduced (P < 0.05) the risk of lesions by about half. Multivariate analyses indicated that pigs in large litters (> 10 pigs at birth) born to sows with postpartum illnesses had an increased risk (relative risk [RR], 3.77) of developing foot abscess, compared with pigs in small litters (< or = 10 pigs) born to unaffected sows. For sows without evidence of postpartum illness, pigs in large litters had a slightly increased risk (RR, 1.32) of developing foot abscess, compared with pigs in small litters. Pigs born to multiparous sows also had an increased risk (RR, 1.69) of developing foot abscess, compared with pigs born to primiparous sows. Similar risk estimates were obtained when logistic regression models included location farrowed (crate number) as a fixed effect, and when litter was a random effect in a logistic-binomial regression.