Myotonia is a congenital muscular condition that is characterized by muscle stiffness and contraction. This is due to a chloride channel disorder, which causes delayed relaxation after muscle contraction.
CLCN1
Autosomal recessive
Affected dogs exhibit a stiff gait and muscle rigidity. This typically occurs after resting, and can subside after normal exercise. The tongue muscle may be affected, which can lead to a protruding tongue. Involuntary muscle contractions can be affected, causing difficulty swallowing or regurgitation after eating.
A veterinarian will conduct a thorough exam, including a review of health history and any clinical signs. A muscle biopsy may be indicated. Genetic testing is necessary to determine if there is an underlying genetic cause, which can assist veterinarians with diagnosis and help breeders identify affected and carrier dogs.
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Smith BF, Braund KG, Steiss JE, Simpson ST, Cox NR, Sorjonen DC. Possible adult onset myotonic dystrophy in a boxer. J Vet Intern Med. 1998 Mar-Apr;12(2):120. PMID: 9560770.
Hill SL, Shelton GD, Lenehan TM. Myotonia in a cocker spaniel. J Am Anim Hosp Assoc. 1995 Nov-Dec;31(6):506-9. doi: 10.5326/15473317-31-6-506. PMID: 8581546.
Shores A, Redding RW, Braund KG, Simpson ST. Myotonia congenita in a Chow Chow pup. J Am Vet Med Assoc. 1986 Mar 1;188(5):532-3. PMID: 3957761.
Shires PK, Nafe LA, Hulse DA. Myotonia in a Staffordshire terrier. J Am Vet Med Assoc. 1983 Jul 15;183(2):229-32. PMID: 6885599.
Disease diagnosis and treatment should always be performed by a veterinarian. The following information is for educational purposes only.
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