Myopathies

Buy now to access the full article, existing subscribers login

Sections available in full article Introduction, Presenting signs, Acute presentation, Age predisposition, Sex predisposition, Breed predisposition, Pathogenesis, Etiology, Pathophysiology, Timecourse (incubation, duration), Diagnosis, Presenting problems, Client history, Clinical signs, Diagnostic investigation, Confirmation of diagnosis, Differential diagnosis, Treatment, Initial symptomatic treatment, Monitoring, Sequelae, Prognosis, Sources, Publications, Vetstream contributor(s),
Contributors Dr Kyle Braund BVSc MVSc PhD FRCVS DipACVIM

Introduction

  • Primary myopathies : masticatory myositis, myotonic myopathies, degenerative breed-specific myopathies, mitochondrial myopathies, muscular dystrophies.
  • Secondary myopathies : paraneoplastic myopathy, endocrine myopathies, inflammatory and nutritional myopathies.
  • Signs : bilateral symmetrical weakness, exercise intolerance, fatigue and stiff, stilted gait.
  • Pain and reflexes are usually preserved.
  • Muscles may hypertrophy or atrophy.
  • Diagnosis : signs, biochemistry, histopathology.
  • Prognosis : guarded.

Diagnosis

Clinical signs

  • Bilaterally symmetrical muscle weakness.
  • Stiff, stilted gait.
  • Localized or generalized muscle atrophy.
  • Generalized muscle hypertrophy.
  • Dimple contractures of muscle following a sudden tap with a hand.
  • Muscle pain on palpation.
  • Limited joint movement.
  • Heat and swelling in the muscles.
  • Megaesophagus.

Diagnosis

Differential diagnosis


Causes of exercise intolerance
  • Cardiac insufficiency Congestive heart failure.
  • Respiratory insufficiency.
  • Myasthenia gravis Myasthenia gravis.
Causes of stiff gait
  • Tetanus Clostridium tetani.
  • Over-exercise.
  • Arthritis Arthritis: osteoarthritis.
  • Episodic falling (Cavalier King Charles Spaniel) Episodic falling (Cavalier King Charles Spaniel).
Causes of weakness
  • Debility of chronic illness or old age.
  • Neuropathies Peripheral neuropathies.
  • Myasthenia gravis Myasthenia gravis.

Causes of muscle atrophy
  • Peripheral nerve trauma Sensory neuropathies.
  • Peripheral nerve neoplasia.
  • Motor neuron disease Motor neurone disease: Brittany Spaniels.
  • Immobilization/disuse.
Causes of generalized muscle hypertrophy
  • High levels of fitness.
  • Use of anabolic steroids.
  • Breeding.
Causes of episodic collapse
  • Epilepsy Epilepsy: idiopathic.
  • Episodic falling (Cavalier King Charles Spaniel) Episodic falling (Cavalier King Charles Spaniel).
  • Cataplexy/narcolepsy.

Sequelae

Prognosis

  • Guarded.

Sources

Publications

Refereed papers

  • Taylor S M (2000) Selected disorders of muscle and the neuromuscular junction. Vet Clin North Am Small Anim Pract 30 (1), 59-75.
  • Platt S R, Chrisman C L & Shelton G D (1999) Lipid storage myopathy in a cocker spaniel. JSAP 40 (1), 31.
  • Braund K G (1997) Degenerative causes of myopathies in dogs and cats. Vet Med 92 , 607-617.
  • Braund K G (1997) Endogenous causes of myopathies in dogs and cats. Vet Med 92 , 618-628.
  • Braund K G (1997) Idiopathic and exogenous causes of myopathies in dogs and cats. Vet Med 92 , 629-634.

Sample content only, to unlock the full article login or buy now

Loading...