Congenital dystrophy-like myopathy in a Brittany Spaniel puppy

A congenital myopathy is reported in the only male puppy from a litter of Brittany Spaniels. The condition was manifested clinically as generalized weakness, mild generalized muscle atrophy and difficulty in eating due to tongue muscle hypertrophy. Creatine kinase values were extremely high. Electromyographically, there were complex repetitive discharges that persisted (pseudomyotonia). Histopathologic examination revealed muscle fiber degeneration, size variation, hyalinization, mineralization, necrosis, and regeneration. Clinical signs, serum biochemistry, electrophysiological and pathological findings of this myopathy have much in common with the canine X-linked muscular dystrophies and with Duchenne muscular dystrophy in humans.A congenital myopathy is reported in the only male puppy from a litter of Brittany Spaniels. The condition was manifested clinically as generalized weakness, mild generalized muscle atrophy and difficulty in eating due to tongue muscle hypertrophy. Creatine kinase values were extremely high. Electromyographically, there were complex repetitive discharges that persisted (pseudomyotonia). Histopathologic examination revealed muscle fiber degeneration, size variation, hyalinization, mineralization, necrosis, and regeneration. Clinical signs, serum biochemistry, electrophysiological and pathological findings of this myopathy have much in common with the canine X-linked muscular dystrophies and with Duchenne muscular dystrophy in humans.A