A clinical study on hereditary progressive neurogenic muscular atrophy in pointer dogs

Three littermates, two males and one female, of the Pointer breed five months of age were affected with hereditary progressive neurogenic muscular atrophy and examined clinically. Atrophy was manifested in the muscles of the four limbs and the trunk, particularly in muscles of the shoulder region. Muscular atrophy and weakness were aggravated in the course of disease. The affected dogs became completely tetraplegic. Dysphonia was also manifested. Frequent fasciculation was observed in most of the superficial muscles. The patellar reflex was diminished markedly, but always present. No cutaneous sensation was involved. No bowel and urinary disturbances were manifested. Consciousness remained to be alert and bright throughout the course of disease. Electromyography revealed widespread fibrillation potentials and positive sharp waves with polyphasic fasciculation potentials. Hematologic examination demonstrated nothing abnormal. One of the dogs died abou t 110 days after the owner noticed the initial sign of the disease, i.e., trembling in the hindliimbs during standing. The other two were subjected to necropsy.