The presence of Dichelobacter nodosus and Fusobacterium necrophorum on the claws of lame dairy cattle in New Zealand

Abstract

Dairy cows face many environmental and management factors that increase the likelihood of lameness, but little is known about the microbiology of lameness. To understand which bacteria may be involved in bovine lameness, samples of debris were scraped from lame claws of dairy cows and examined for the presence of Fusobacterium necrophorum (F. necrophorum) and Dichelobacter nodosus (D. nodosus) using the polymerase chain reaction (PCR). F. necrophorum was detected in 79/148 of the samples, while D. nodosus was detected in 7/148 of the samples. The frequent finding of F. necrophorum on lame dairy cattle is noteworthy and the occasional finding of D. nodosus on some lame claws, suggested a possible role in bovine lameness. The presence of F. necrophorum was further investigated on the claws of cattle, sheep and goats with symptomatic footrot. Of the nine samples from cattle, all were positive for F. necrophorum and eight of these carried a variant of F. necrophorum that matched the type strain of F. necrophorum subsp. necrophorum. Of the 20 samples from sheep and goats, 18 were positive for F. necrophorum and 14 of these carried a different variant of F. necrophorum. This suggests that cattle may be infected by a F. necrophorum strain different to those affect sheep and goats. In contrast to D. nodosus, there was no evidence of mixed-strain infection for F. necrophorum in hooves.