Growth Plate Lesions of 62 Fattening Bulls From An Abattoir In The North-East of Italy

Introduction: Lameness caused by growth plate lesions is a problem in beef cattle; however, there are no recent reports on this topic. This paper describes the macroscopic and microscopic lesions of the distal metatarsal physis of bulls from farms in North-Eastern Italy. Materials and Methods: The distal metatarsal physes from 62 bulls of 16.44 1.72 months of age were examined; 12 bulls were slaughtered due to severe lameness (group A) and 50 were slaughtered with no signs of lameness (group B). Animals were from the same area and shared similar intensive husbandry practices and diet. Grossly, 124 metatarsi were examined. Four distal metatarsal bones from grossly normal bulls, 24 from group A and 18 from group B with macroscopic lesions, were examined microscopically. Results: Macroscopic lesions present in group A bulls included one example of bilateral purulent chronic physitis (PCP), seven of unilateral PCP, three of bilateral physeal osteochondrosis (OCD), six of unilateral OCD and three of unilateral purulent tenosynovitis. Nineteen bulls (38%) from group B also had macroscopic OCD lesions (13 bilateral and six unilateral), confirmed by histology in six cases. On microscopic examination, severe segmental thickening of the hypertrophic zone was present, consistent with physeal OCD. In animals with PCP, the physis was necrotic with eosinophilic cartilage matrix, extensive neutrophilic infiltrate, haemorrhage and fibrin deposition. Conclusions: A high incidence of OCD was found in lame and nonlame fattening bulls. Haematogenous bacterial implantation in the metaphysis led to a purulent physitis that resulted in severe lameness and necessitated emergency slaughter of affected animals.