Noise aversion describes a true phobia (mental disorder) triggered by a particular noise or loud noises in general. It affects approximately 30% of dogs.
Nonsteroidal anti-inflammatory drugs (NSAIDs) toxicosis is the ingestion of a toxic or lethal dose of a NSAID.
Narcolepsy is a sleep disorder affecting the brain characterized by excessive daytime sleepiness and spontaneous or emotion-triggered collapse (cataplexy). This is an uncommon condition in dogs, and can be caused by a genetic predisposition or in rare cases, a brain disorder or nerve disease.
Nasal mites (Pneumonyssus caninum) are a species of parasitic arachnids commonly found in the nasal cavity of dogs. Nasal mites affect up to a quarter of the canine population in some areas.