Common Symptoms
Narcolepsy (dachshund type) is an inherited disorder affecting dogs. Dogs with the inherited form of narcolepsy typically present between one to six months of age with an inability to stay awake for extended periods of time and episodes of collapse and sleep following positive stimulation such as play or food. Affected dogs fall asleep faster than normal dogs and appear sleepy more frequently. During episodes of collapse dogs have a sudden loss of muscle tone and appear uncontrollably sleepy but may or may not completely fall asleep. Symptoms do not progress after one year of age and affected dogs do not have other associated health problems.
Breed-Specific Information for the Miniature Wirehaired Dachshund
Miniature wirehaired dachshund is included as a breed susceptible to narcolepsy (dachshund type) because of its close relatedness to the standard smooth dachshund breed, which is known to develop this disease due to Mutation of the HCRTR2 gene. The frequency of the causal mutation in the general miniature wirehaired dachshund population is unknown.
Testing Tips
Genetic testing of the HCRTR2 gene in miniature wirehaired dachshunds will reliably determine whether a dog is a genetic Carrier of narcolepsy (dachshund type). Narcolepsy (dachshund type) is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the HCRTR2 gene mutation. Reliable genetic testing is important for determining breeding practices. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Miniature wirehaired dachshunds that are not carriers of the mutation have no increased risk of having affected pups.
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
References
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Chen L, Brown RE, McKenna JT, McCarley RW. Animal models of narcolepsy. CNS Neurol Disord Drug Targets. 2009 Aug;8(4):296-308.
[PubMed: 19689311]
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Hungs M, Fan J, Lin L, Lin X, Maki RA, Mignot E. Identification and functional analysis of mutations in the hypocretin (orexin) genes of narcoleptic canines. Genome Res. 2001 Apr; 11(4):531-9.
[PubMed: 11282968]
