"My heart is broken because a coyote took my precious Daisy right in front of our eyes," Simpson wrote on her Twitter. "HORROR! We are searching. Hoping. Please help!"
Daisy, a five-year-old maltipoo, was a gift to Jess from ex-husband Nick Lachey. The pooch has been by Jessica's side ever since, traveling with the reality star to worldwide events.
Simpson recently wrapped shooting her VH1 reality show "The Price of Beauty" in Brazil.