People.com said the singer-actress is offering a reward for the return of her 5-year-old, caramel-colored maltipoo.
The report did not specify the amount of the award or the location of where the pup disappeared.
"My heart is broken because a coyote took my precious Daisy right in front of our eyes. HORROR!" Simpson said on her Twitter page. "We are searching. Hoping. Please help!"
TMZ said the dog was a gift from Simpson's ex-husband, Nick Lachey.
2014: The Year in Fashion [PHOTOS]
Reports: Mila Kunis gives birth to baby girl