Evaluation of subclinical laminitis in a dairy herd and observations on associated nutritional and management factors.

The hind claws of 10 heifers, 10 second-calf cows, and 10 mature cows in the University of Saskatchewan's dairy herd were examined on four consecutive occasions, four and two months before calving, at calving, and two months after calving. A high prevalence of haemorrhages was observed in the sole of the claws, and these lesions were most prevalent near calving; the haemorrhages were detected in the heifers up to four months before calving. After calving, the haemorrhages tended to disappear rapidly from the claws of the heifers, but no such recovery was evident in the second calvers and mature cows. A scoring system for sole haemorrhages was developed, and the different scores were linked with sole ulcer (pododermatitis circumscripta), toe ulcer, white zone lesions, and heel erosion. Factors associated with nutrition and management, such as rapid rearing (average daily weight gain from birth to breeding greater than 800 g), the sudden introduction into the dry group after they had been confirmed pregnant, confrontation by dominant cows, and housing on concrete in a cubicle system appeared to play a role in the occurrence of haemorrhages in the claws of heifers well before calving.