Scotty cramp

From Dog

Scotty cramp is an autosomal-recessive genetic neurological disease of Scottish Terrier and Cesky Terrier breeds characterized by episodic hypertonia and kyphosis ('cramps')[1].

In clinically affected dogs, ataxia usually presents as pelvic limb hypertonicity and kyphosis without signs of pain and can be induced with minimal exercise. Normal ambulation is restored following a period of rest[2]. Symptoms usually worsens with age but rarely become life threatening.

The disorder appears to be due to a deficiency in concentrations or function of serotonin in the CNS and decreasing CNS concentrations of serotonin via para-chlorophenylalanine (pCPA) will profoundly increase the severity of the disease although the basic defect does not involve serotonergic neurons[3].

Definitive diagnosis can be established by muscle biopsies and trial injections of methysergide, where symptoms markedly worsen.

A differential diagnosis would include myasthenia gravis, neuromyotonia, microseizures[4] and electrolyte abnormalities associated with hypoparathyroidism[5] and hypoadrenocorticism[6].

Most dogs respond to oral supplementation of fluoxetine[7].

Administration of benzodiazepines, vitamin E, or phenothiazines has been recommended for treatment of episodes of hypertonicity, but often does not result in control of clinical signs.

References

  1. Meyers KM et al (1969) Hyperkinetic episodes in Scottish Terrier dogs. J Am Vet Med Assoc 155(2):129-133
  2. Andersson B & Andersson M (1982) On the etiology of "Scotty Cramp" and "Splay" - two motoring disorders common in the Scottish Terrier breed. Acta Vet Scand 23(4):550-558
  3. Schaub RG & Meyers KM (1975) Evidence for a small functional pool of serotonin in neurohumoral transmission. Res Commun Chem Pathol Pharmacol 10(1):29-36
  4. Garosi L & Harvey RJ (2012) Scottie cramp and canine epileptoid cramping syndrome in Border terriers. Vet Rec 170(7):186-187
  5. Russell NJ et al (2006) Primary hypoparathyroidism in dogs: a retrospective study of 17 cases. Aust Vet J 84(8):285-290
  6. Saito M et al (2002) Muscle cramps in two standard poodles with hypoadrenocorticism. J Am Anim Hosp Assoc 38(5):437-443
  7. Geiger KM & Klopp LS (2009) Use of a selective serotonin reuptake inhibitor for treatment of episodes of hypertonia and kyphosis in a young adult Scottish Terrier. J Am Vet Med Assoc 235(2):168-171