Canine narcolepsy is a neurological sleep disorder with autosomal recessive inheritance, characterised by excessive sleepiness and cataplexy (sudden loss of muscle tone triggered by emotions such as food or play, without loss of consciousness). In the Doberman it is associated with an insertion of a SINE element in intron 3 of the HCRTR2 gene, which encodes the hypocretin/orexin receptor 2. It is neither progressive nor life-threatening, but it affects quality of life.

Narcolepsy with cataplexy documented in the Doberman, associated with the HCRTR2 variant. Other breeds (Labrador, dachshund, Dogo Argentino) present different variants of the same gene.

- Excessive daytime sleepiness and episodes of rapid-onset sleep
- Cataplexy triggered by food, play or emotions
- Sudden collapse with flaccid muscles, retaining consciousness and with the eyes open
- Episodes lasting seconds to minutes
- Onset between 4 weeks and 6 months of age
- Non-progressive and non-fatal course

Narcolepsy with cataplexy was described in the Doberman and the Labrador as a natural model of human narcolepsy. In 1999, Lin and co-workers identified the HCRTR2 gene mutation as the cause of the disease by positional cloning, a finding that linked the hypocretin/orexin system to sleep regulation. Later studies described different mutations in other breeds (Labrador, dachshund, Dogo Argentino).

- Test Doberman breeding animals with the HCRTR2 test before breeding
- Do not mate two carriers (25% affected offspring)
- A carrier may be mated to a clear animal; test the offspring intended for breeding
- Avoid the massive use of carrier lines
- Inform that the disease is compatible with a good quality of life and can be managed with symptomatic treatment

The differential diagnosis includes epilepsy, syncope, neuromuscular disease and other sleep disorders. The genetic test confirms the status. Cataplexy can be treated with tricyclic antidepressants (imipramine, clomipramine). The HCRTR2 test detects the known mutations in the Doberman and Labrador; not all breeds with narcolepsy share the same variant.

1. Lin L et al. 1999. The sleep disorder canine narcolepsy is caused by a mutation in the hypocretin (orexin) receptor 2 gene. Cell. PMID: 10458611
2. Boehmer LN et al. 2004. Treatment with immunosuppressive and anti-inflammatory agents delays onset of canine genetic narcolepsy and reduces symptom severity. Exp Neurol. PMID: 15246829
3. Mondino A et al. 2025. Familial Narcolepsy in Dogo Argentino Dogs Is Caused by a Tandem Duplication Mutation in HCRTR2. J Vet Intern Med. PMID: 40095233
4. OMIA:000703-9615.