Episodic mandibular tremor in dogs: an idiopathic movement disorder or a manifestation of pain.

Abstract

Episodic mandibular tremor (EMT), manifested as teeth chattering, is not well described in dogs. The aim of this study was to describe clinical signs, MRI findings, and outcome of dogs with EMT. 11 dogs retrospectively and 31 dogs in an online survey. A retrospective multicenter study of dogs with EMT between 2018 and 2023 and prospective online questionnaire open to owners of pets with teeth chattering. All dogs had rapid and short-lasting (< 1 minute) episodes of EMT in the absence of other neurological signs. Lip smacking occasionally accompanied the tremor in 5 of 11 (45.5%) hospital dog cases. Excitement was a common trigger in 14 of 31 (45.2%) dogs from the survey. Cavalier King Charles Spaniel was the most common breed in both clinical and survey populations. Median age at presentation was 3 years for both hospital cases and the survey dogs. A concurrent medical condition was present in 8 of 11 (72.7%) hospital cases and 20 of 31 (64.5%) survey dogs. In 3 hospital dogs that underwent further investigations, no brain disease was present. EMT and its clinical features are presented for the first time, shedding light on a clinical sign that might resemble an idiopathic movement disorder or a manifestation of pain in dogs.