Myotonia in a cocker spaniel.
A 16-week-old, male cocker spaniel suffering from pelvic-limb "bunny hopping" as well as rigidity, spasticity, and ataxia in all limbs was evaluated. The clinical features, electrophysiological abnormalities, and muscle histopathological and histochemical evaluations led to a diagnosis of congenital myotonia. Myotonia is a disorder of skeletal muscle characterized by delayed relaxation of the muscle fiber in response to voluntary, mechanical, or electrical stimulation. The pathophysiology of congenital myotonia remains controversial; currently proposed pathomechanisms are discussed. To the authors' knowledge, this is the first case of congenital myotonia reported in a cocker spaniel.
Hill
S L
SL
San Diego Veterinary Referral Services, California 92108, USA.
Shelton
G D
GD
Lenehan
T M
TM
D000818:Animals; D001706:Biopsy / Q000662:veterinary; D004283:Dog Diseases / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D004285:Dogs; D004558:Electric Stimulation; D004576:Electromyography / Q000662:veterinary; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000502:physiology / Q000648:ultrastructure; D009126:Muscle Relaxation / Q000502:physiology; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology; D009222:Myotonia / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary*