RED: SEVERE SIGNS – FIGHT/ AGGRESSION (FAS LEVEL 5)

Offensive aggression: pupils constricted or dilated, cat leaning forward, ears forward, moving forward, whiskers forward, tail is an inverted L (first inch of tail is horizontal with ground then the tail drops down), rump raised higher than front (on tip toes), staring, may be growling
Defensive aggression: ears back, pupils dilated, hunkered down, tail tight or tucked or tail thrashing, whiskers back, hissing, lips pulled back, staring, furrowed brow, could be swatting

RED: SEVERE SIGNS – FLIGHT/FREEZE/FRET (FAS LEVEL 4)

Flight: actively trying to escape, pupils dilated, ears back, whiskers back, tail down and bottle brushed, fleeing, turning to look at stimulus
Freeze/Fret: tonic immobility, dilated pupils, body flattened and tense, tail tucked, increased respiratory rate, ears back, staring, whiskers back

YELLOW: MODERATE SIGNS (FAS LEVEL 2-3)

Ears further to the side, more pupil dilation but not completely dilated, increase in respiratory rate, brow furrowed, looking at stimulus instead of looking away, tail tight to body, possible tip of tail moving some, whiskers back, body crouched and leaning away

GREEN: MILD/SUBTLE SIGNS (FAS LEVEL 1)

Avoids eye contact, turns head away without moving away, partially dilated pupils, head held just slightly down, slight brow furrowing, whiskers slightly back, ears partially to the side, body shifted slightly away, tail closer to body with possibly some slight flicking

GREEN: PERKED/INTERESTED/ ANXIOUS? (FAS LEVEL 0-1)

Looking directly but not intensely, tail up and winding, mouth closed with loose lips, ears perked forward, whiskers forward, slight pupil dilation

GREEN: RELAXED (FAS LEVEL 0)

Sleeping
Neutral: Ears in neutral position, brow soft, eyes soft, mouth closed with relaxed lips, body loose, tail carriage U-shaped, pupils normal dilation
Friendly greeting: Tail up and winding, may elevate rear end slightly by standing on toes, ears neutral, forward, or slightly back, might have squinty eyes, brow relaxed, might cheek mark or rub on person or object

The Spectrum of Fear, Anxiety, and Stress