Affected dogs develop clinical signs at 8 to 10 weeks of age. Signs include a shuffling gait or shortened stride (?bunny hopping?), inability to completely open the jaw, difficulty eating, thickening of the base of the tongue, excessive salivation, abduction of front paws, adduction of stifles and hocks, and prominent wasting of temporal and trunk muscles (Shelton, 2004; Valentine et al., 1992; Kornegay et al., 2011). Other signs include spinal and costal curvature, resulting in a crouched posture (Valentine et al., 1992). Elevated serum creatine kinase concentrations (up to 300 times greater than normal) begins during the first week of life age, and is exacerbated by exercise (Valentine et al., 1992). In breeds where a mutation has not been reported, affected dogs can be tentatively diagnosed by immunohistochemical tests for the presence or absence of dystrophin protein in skeletal muscle biopsy (Shelton and Engvall 2002) [From OMIA, accessed 2019]