Acute phase response in lame cattle with interdigital dermatitis.

This study was undertaken to evaluate acute phase response via assessing the concentration of serum sialic acids (total, lipid-bound and protein-bound), inflammatory mediators (IFN-γ and TNF-α) and acute phase proteins [haptoglobin (Hp) and serum amyloid A (SAA)] in lame cattle with interdigital dermatitis. Fifteen hoof scrapings from lame cows were collected from eight commercial dairy farms. As a consequence of the difficulty in culturing and isolation, a PCR technique was used to detect the organism. None of the colonies on enriched blood agar was identified as Fusobacterium necrophorum. Four (26.6%) out of the 15 hoof scrapings examined tested positive for the presence of the lktA gene (402 bp) of F. necrophorum. It seems that culture cannot be considered as the gold standard method for F. necrophorum isolation. Molecular detection is suggested as an alternative method. In the blood serum of different groups of animals (control, lameness and F. necrophorum-positive lameness) Hp, SAA, total sialic acid, lipid-bound sialic acid, and protein-bound sialic acid, and IFN-γ and TNF-α were measured using validated standard procedures. All parameters were significantly higher in the lameness group and the F. necrophorum-positive lameness group compared with the healthy group (P < 0.01 in all cases). Mean SAA concentrations in the lameness group and the F. necrophorum-positive lameness group was relatively 4.6 and 8.0 times higher than the control group. Corresponding measures for Hp indicate a 3.3 times increase in the lameness group compared to the control. In the lameness group, significant associations were observed for Hp with PBSA, SAA with TSA, TSA with PBSA, TSA with LBSA, PBSA with LBSA, and SAA with IFN-γ.