Causes include infections of the dam with Akabane virus, Aino virus, Palyam virus and Pestivirus (Mucosal disease) and Border disease), as well as inherited defects.

Diagnosis

Based on clinical signs and gross pathology. Diagnosis of the cause depends on history and samples from the dam and affected animals.

Specimens required

1. Sample of foetal pericardial or pleural fluid submitted chilled for virus isolation and serology, or, a blood sample from the neonatal animal if it has not sucked.
2. Serum sample from the dam, submitted chilled for serology.
3. Brain and spinal cord in buffered formalin for histopathology.
   
   NB.
   Arthrogrypotic animals may have CNS lesions only in the spinal cord.
   
4. Sections of extensor muscles in buffered formalin for histopathology.