Myelodysplasia as a cause of hindlimb ataxia in two beef calves

Abstract

Myelodysplasia is a general term referring to abnormal development of the spinal cord. Unless associated with vertebral malformations, it can be difficult to distinguish clinically from other causes of spinal cord disease. These case reports describe the clinical and pathological findings in two calves with a distinctive non-progressive pelvic limb ataxia. The syndrome was observed in two calves on a large, extensively managed beef cattle property near Richmond, north Queensland. Both calves had similar clinical signs, including hindlimb ataxia with swaying of the pelvis and a well-coordinated bilateral hopping-like action. The differential diagnoses are discussed. A focal or diffuse myelodysplasia should be suspected in calves that have exhibited a non-progressive hindlimb ataxia from birth.

Recurrent Outbreaks of Myelodysplasia in Newborn Calves

“…However, two cases of myelodysplasia without skeletal deformities, similar to those described here, have been reported in cattle, but these were restricted exclusively to the lumbar cord (Imai and Moritomo, 2009;Hill, 2010). In contrast to these reports, the entire length of the spinal cord was affected in the present cases, a feature which, to our knowledge, has not been reported previously.…”

“…Congenital defects of the CNS have been described in ruminants, with spinal cord malformations being more commonly reported in calves than in smaller ruminants, but the aetiology of these defects remains unconfirmed. Previous reports of myelodysplasia have usually affected one or two calves (Leipold et al, 1977(Leipold et al, , 1993Hiraga and Abe, 1987;Doige et al, 1990;Summers et al, 1995;Ohfuji, 1999;Imai and Moritomo, 2009;Hill, 2010), whereas in the recurrent outbreaks studied here, morbidity was up to 30% in the affected flocks, over a period of at least 15 years.…”

“…There are few reports of this pathological change in cattle and these were isolated cases that affected only a small number of animals and were often associated with skeletal deformities, cleft palate and arthrogryposis (Leipold et al, 1977(Leipold et al, , 1993Hiraga and Abe, 1987;Doige et al, 1990;Ohfuji, 1999;Imai and Moritomo, 2009;Hill, 2010). Myelodysplasia has been related to genetic factors in Charolais and Hereford calves, although the mode of inheritance is unknown (Leipold et al, 1969).…”

Syringomyelia in a Newborn Male Simmental Calf

“…Without skeletal abnormalities it can be difficult to clinically distinguish these abnormalities from other causes of spinal cord diseases. 24 Whereas, in this case, there were no vertebral malformations, the syringomyelia was combined with abnormalities of both the central canal and the ventral fissure. Although the central canal was significantly narrowed over several segments, there were no signs of a subsequent dilatation or hydromyelia elsewhere as might be expected because of a raised CSFP.…”

“…These changes can be associated with vertebral malformations leading to spina bifida or myelomeningocele. Without skeletal abnormalities it can be difficult to clinically distinguish these abnormalities from other causes of spinal cord diseases 24. Whereas, in this case, there were no vertebral malformations, the syringomyelia was combined with abnormalities of both the central canal and the ventral fissure.…”