I recently read a book called "The beast in the Garden". It's about the cougars in Boulder and Idaho Springs. One cougar killed a highschool kid who was an athlete and just on his training run.
The cats were getting use to being around humans, and had started seeking dogs as food. (It was originally believed that cougars were afraid of dogs because of their agressive nature and loud bark)
"It was originally believed that cougars were afraid of dogs because of their aggressive nature and loud bark, but it appears that the readily available bloody meat supply and dog's savory and complex bouquet proved very tempting, so the wolves just eat them, bark and all."
An appetizing taste treat for the entire pack, and associated hybrids.