Frequency and animal demographics of mouthing behavior in companion dogs in the United States

•Mouthing behavior was common in dogs and occurred at higher rates in dogs under 1 year old.•Owners of dogs which mouthed at high frequencies or produced injuries were more likely to want the behavior reduced.•Owner behavior in response to their dog's mouthing was often contraindicated relative to the hypothesized function.•Dogs which played tug games were no more likely to bite than dogs which did not play tug. Problem behavior in companion animals can result in reduced quality or length of life for the animal, as well as stress for the human owners. In particular, mouthing is commonly described by dog owners as problematic (Shabelansky & Dowling-Guyer, 2016). However, there is a paucity of both descriptive and inferential data on the frequency or predictors of the behavior. The purpose of this study was to provide population-level data on mouthing behavior in companion dogs in the United States. Although there is known disagreement about the definitions of biting and mouthing behavior, mouthing was defined for this study as behavior where the dog’s teeth or inner lips touch human skin or clothing. Data collected via surveys from dog owners indicated that a high percentage of the dog population engages in mouthing and that many owners find the behavior to be undesirable. Analyses indicated that the prevalence of this behavior is significantly correlated with age, although many dogs continue mouthing into adulthood. Additionally, the frequency and severity were also negatively correlated with age and owner desire to reduce the behavior. Future research should address disagreement on the labels and definitions of mouthing versus biting and experimentally assess efficacious interventions to reduce mouthing in young dogs and avoid mouthing in adult dogs.