Narcolepsy

From Dog

Narcolepsy is an autosomal-recessive genetic disease of dogs.

Narcolepsy is a debilitating sleep disorder with excessive daytime sleepiness and cataplexy as its two major symptoms[1]. The genetic disorder is thought to result in hypocretin (orexin) neurotransmission deficiency[2], resulting in uncontrollable sleep patterns[3]. An autoimmune etiology has been suggested for narcolepsy but never proven[4].

This disease has been reported in the Dachshund, Doberman, Labrador Retriever and Labradoodle[5].

Affected dogs appear to fall asleep, suddenly losing control of their hind legs or collapsing in complete paralysis, while still being entirely aware of their surroundings. Attacks last from a few seconds to a few minutes and end with no residual effects.

Some sporadic cases of narcolepsy are not inherited.

Clinically affected dogs have been treated with SSRI antidepressant drugs such as venlafaxine[6], but with limited success.

Use of stimulant drugs such as methylphenidate, amphetamine[7] or selegiline may provide some remedial therapy, although clinical trials are as yet lacking.

References

  1. Chen L et al (2009) Animal models of narcolepsy. CNS Neurol Disord Drug Targets 8(4):296-308
  2. Santamaria-Cano J (2012) Diagnostic and therapeutic update in narcolepsy. Rev Neurol 54(3):S25-S30
  3. Kalogiannis M et al (2010) Narcoleptic orexin receptor knockout mice express enhanced cholinergic properties in laterodorsal tegmental neurons. Eur J Neurosci 32(1):130-142
  4. Hallmayer J et al (2009) Narcolepsy is strongly associated with the T-cell receptor alpha locus. Nat Genet 41(6):708-711
  5. Lin L et al (1999) The sleep disorder canine narcolepsy is caused by a mutation in the hypocretin (orexin) receptor 2 gene. Cell 98:365–376
  6. Delucchi L et al (2010) Use of venlafaxine in the treatment of a canine narcolepsy-cataplexy case. J Small Anim Pract 51(2):132
  7. Kanbayashi T et al (2000) Implication of dopaminergic mechanisms in the wake-promoting effects of amphetamine: a study of D- and L-derivatives in canine narcolepsy. Neuroscience 99(4):651-659