Supplementary Table II.
Descriptions of behavioral parameters and criteria for evaluating dogs consuming a complete and balanced dry diet containing graded concentrations of supplemental tryptophan (Trp) at 0% (control), 0.05%, 0.1%, and 0.15%.
| Behavioral parameter | Description of behavior |
|---|---|
| Pen position (evaluation of pre-kennel-entry period) | The dog’s position relative to the kennel gate (at the front of the pen) in response to an individual (familiar/unfamiliar) approaching its kennel gate. 1 signifies a dog located as far at the back of the pen as possible and 10 signifies a dog jumping at the kennel gate. |
| Activity level (evaluation of post-kennel-entry period) | The dog’s level of activity or excitability in response to an individual (familiar/unfamiliar) entering its kennel. 1 signifies a dog remaining completely inactive and 10 signifies a dog that is uncontrollably/overly active, e.g., excessive pacing/circling. |
| Distance from approaching individual (evaluation of post-kennel-entry period) | The dog’s position relative to an individual (familiar/unfamiliar) entering its kennel. 1 signifies a dog that is the maximal distance from the individual and 10 signifies a dog that is as close to the individual as possible, e.g., physical contact with or jumping on the individual. |
| Response to approach (evaluation of post-kennel-entry period) | The apparent attitude of the dog in response to an individual (familiar/unfamiliar) entering its kennel. 1 signifies a dog demonstrating avoidance-related behaviors, e.g., unresponsive upon entry, ears and tail low, lack of eye contact, refusal of interaction, and 10 signifies a dog demonstrating affiliative and affectionate behavior, e.g., actively wagging tail, relaxed/open mouth, vigorous gait, may vocalize, ears forward, seeking interaction. |
| Confidence (evaluation of post-kennel-entry period) | The degree of confidence-related behavior the dog directs towards an individual (familiar/unfamiliar) entering its kennel. 1 signifies a dog demonstrating human-oriented fearfulness, e.g., cowering, low posture, tail tucked or depressed, maintaining eye contact but avoiding close proximity, and 10 signifies highly confident behavior, e.g., front-sided and direct approach, resting tail, ears forward, close visual, olfactory, and/or gentle oral inspection. |
| Posture (evaluation of post-kennel-entry period) | The dog’s posture or stance in response to an individual (familiar/unfamiliar) entering its kennel. 1 signifies a dog that is lying down on its side, 5 signifies a dog crawling sternally, and 10 signifies a dog actively walking or moving. |
| Tail position (evaluation of post-kennel-entry period) | The position of the dog’s tail in response to an individual (familiar/unfamiliar) entering its kennel. 1 signifies the dog’s tail is tightly tucked between its legs, 5 signifies a resting tail, and 10 signifies a tail that is held high and actively wagging. |
| Ear position (evaluation of post-kennel-entry period) | The position of the dog’s ears in response to an individual (familiar/unfamiliar) entering its kennel. 1 signifies ears that are completely laid back and 10 signifies ears that are fully erect and facing forward. |
| Aggression (evaluation of post-kennel-entry period) | The degree of aggressive behavior a dog directs towards an individual (familiar/unfamiliar) entering its kennel. 1 signifies a complete absence of aggressive behavior and 10 signifies extreme aggression, e.g., hackles raised, lips curled, growling, stiffened posture, lunging, snapping, and attempting to bite. |