Table 3.

Ethogram of behaviors tracked by a single trained observer blinded to treatments using The Observer XT (Noldus Information Technology Inc., Leesburg, VA).

Behavioral category	Behavior	Definition used
Movement	Inactive	Standing still, sitting, or laying down
	Cowering	Sudden cessation of movement in response to a stimulus
	Pacing	Frantically moving back and forth, restlessness
	Destruction	Scratching or chewing at room furnishings
Eyes	Facing door	Eyes are focused on the door of the room
	Glancing around	Eyes are shifting back and forth, possibly looking for the source of a sound
	Other	Eyes are focused on something else in the room
Ears	Ears relaxed	Ears are held in natural position
	Ears erect	Ears raised in response to stimulus
	Ears moving	Ears moving back and forth
Tail posture	Tail relaxed	Tail is not rigid and is lower than the top of the body
	Tail stiff	Tail is rigid and horizontal
	Tail wagging	Tail is wagging back and forth
	Tail tucked	Tail is tucked between hind legs
Muzzle	Barking	Emitting a short, loud sound
	Whining	Emitting a long, high pitch sound, often repeated
	Panting	Mouth open wide with tongue protruding while breathing heavily
	Licking	Using the tongue on own body or another object
	Yawning	Opening the mouth wide and inhaling
	Biting	Using teeth on the door or object