My 24 yr. old cat died recently (at home, in her bed)& I'm devastated I wasn't there for her. She only weighed 4 pounds & I'd only left her for 3 hours - but when I came home, she was already "stiff" (rigor mortis). I'm trying to determine when she died, & I'm hoping it wasn't "minutes" after I left! Someone told me it only takes 1 hour for rigor mortis to set in, in a small cat. My girl was only 4 lbs. with no real diseases. How long did it take for rigor mortis to set in? Thank you very much for any help!