2007 Volume 16 Issue 3 Pages 71-76
Canine narcolepsy is characterized by cataplexy, a sudden loss of muscle tone while awake and active, and is typically triggered by emotional stimulation such as play or the presentation of food. Compounds enhancing monoaminergic neurotransmission have been reported to reduce cataplexy. We report a male Chihuahua with hypocretin-deficient narcolepsy that was treated with four anticataplectic agents in sequence at various dosages for more than four years since age two: imipramine (tricyclic antidepressant), yohimbine (alpha-2 adrenoreceptor antagonist), sulpiride (D2/D3 antagonist), and milnacipran (serotonin-and noradrenaline-selective reuptake inhibitor) were given orally. A single kind of medicine was continuously administered for a certain period of time, and switched to another, after judging the curative effects. Numerical evaluation showed that all agents except sulpiride reduced cataplexy, and that yohimbine, which was used most repeatedly for the longest period in total in this case, was steadily effective against cataplexy and also reduced the dog's daytime drowsiness without side effects. In clinical practice, careful selection of anticataplectic agents is necessary because the preferable medicine may differ depending on species and/or individual variation.
