Muscular dystrophy (MD)

Muscular dystrophy (MD) is a slowly progressive, hereditary muscular atrophy.\n\nMuscular dystrophy in Cavalier King Charles Spaniel, Golden Retriever and Norfolk Terrier is a spontaneous, X-linked, progressively fatal disease of dogs. Affected dogs show raised creatine kinase levels, muscle atrophy with contractures, hyaline myofiber degeneration with mineralization, endomysial and perimysial fibrosis with fatty infiltration, and cardiomyopathy. \n\nLandseer muscular dystrophy is inherited as an autosomal recessive trait. Affected dogs exhibit a general, whole body muscular weakness, they move slowly and clumsy and some cannot walk at all. First symptoms in the course of movement appear at the age of three to six month. Affected dogs usually die between the ages of 4 and 24 months.\n\nIn the breed American Staffordshire Terrier, a variant of the COL6A3 gene has been identified to cause congenital muscular dystrophy. First symptoms like progressive gait abnormalities and joint contracture become obvious at the age of 6 months. Affected dogs show diffuse muscle atrophy and multifocal joint contracture with reduced range of motion and marked thickening of the elbow and stifle joints, along with distal limb joint hyperlaxity. Additional symptoms are severe generalized weakness, such that they had difficulty rising and ambulating, as well as ambulatory tetraparesis with a stiff, choppy, short-strided gait in all limbs without obvious ataxia. Weak withdrawal reflexes were seen in all limbs.\n