Table 2.

Behavioural terms and definitions used to assess dog emotion during test sessions.

Term	Definition
Whining	Dog produces sounds such as whines, whimpers, yelps, etc. originating from the throat and mouth38
Not Whining	Sound production ceases38
Panting	Increased shallow respiration through an open mouth, may have tongue out47
Mouth not visible	Can not see mouth area. Panting/Not Panting cannot be determined (defined for this study)
Not Panting	Mouth is closed—normal breathing resumes38
Yawn	An involuntary intake of breath through a wide-open mouth38
Shake	Dog's whole body and/or head starts moving rapidly from side to side while the dog stands48
Bark	Head and lips forward, mouth opening and shutting repeatedly to omit a large, sharp, short sound emitted from the throat38
Howl	Raised muzzle perpendicular to ground and emits a long, drawn-out sound through semi-closed jaws. Stops when dog lowers head and/or when sound is no longer produced (modified)38