Spastic paresis in calves
SIR, - I wish to report the occurrence of hindlimb straightness and stiffness with inability to flex the hock in calves, in a herd of 21 pedigree Simmental cows that calved in the spring of 2003. Six of eight female calves were affected, with 13 unaffected males. The age of onset was from
Bovine asymmetric hind limb paresis, a presumptive in-utero plant poisoning.
Summary: A new locomotory disturbance of cattle is described. The condition has occurred sporadically since the mid-1980s. Affected herds had all grazed flood plain pastures in a restricted area of north-western New South Wales. Calves were either born with clinical signs or developed them by 4 months of age. The disease was characterised by a slowly progressive, irreversible, asymmetrical, paresis of the hind limbs. Affected cattle experienced persistent hyper-extension of the hip and stifle joints. Macroscopic and microscopic examination of the nervous and musculoskeletal systems failed to demonstrate abnormalities that would account for the clinical signs. The disorder shares many similarities with bovine spastic paresis. It is suggested that the pathogenesis of the disorder is nervous, and probably involves nigro-striatal, medulla oblongata, and spinal dysfunctional inputs. An in-utero plant poisoning was suspected but no specific plant association was determined.
Suspected poisoning of sheep by Ixiolaena brevicompta.
A mortality in sheep attributed to poisoning by Ixiolaena brevicompta is described. Clinical signs included reduced exercise tolerance, weakness and recumbency or sudden death. Elevated serum creatinine phosphokinase concentration and dystrophic muscle lesions were found consistently. Extensive losses occurred but only in sheep forced to eat herbage in which mature, seeded I. brevicompta predominated.