Quadriceps muscle hypoplasia causing congenital lameness in Holstein calves
Gordon, P.J.; Oxby, N.
Veterinary Record 136(18): 476
1995
ISSN/ISBN: 0042-4900 PMID: 7638942 Document Number: 447264
Four cases of congenital hindleg lameness in male and female Holstein calves which had been unable to extend the stifle and bear weight are reported. Hypoplasia of the quadriceps muscle group which could be palpated as a fibrous band along the cranial aspect of the femur involved one or both limbs. PM examination of one calf revealed that the affected muscle comprised myofibrils of variable size, the majority of which were markedly reduced in diameter. Immunohistochemistry suggested they were immature fibres. The femoral nerve sections appeared normal but in the spinal cord there was a reduced number ventral motor neurons on the affected side compared to the control side. It is suggested that the lameness was due to quadriceps hypoplasia secondary to the failure of adequate innervation of the muscle.