Bryant Redhawk
Songster
So sorry for your loss. I can't help ID the predator.
Coopers hawks are small- only about 18" long and weigh about a pound. They usually eat songbirds like robins but could kill chickens. Doubt a 1# bird could carry a 20# dog though!
I've seen them kill and eat prey on the ground. Around here, (we have several nests nearby), there is often a pile of scattered feathers. They leave carcasses too.
Sorry, I didn't specify that the two I've seen were puppies. They don't weigh 20 lbs. These pups were around 6 weeks old and may have been up to around 5-7 lbs. Quite within the range of what just about any hawk larger than a sharp shinned can carry.
Your information, while accepted, is not complete.
Cooper's hawks currently have a measured average of around 18" they can be 20 inches or some even a little larger than that. Size depends somewhat on how much food they get as they grow. The currently measured average wing span (which is the real determiner of power at takeoff and in flight) can be as much as 39-40 inches, with again the odd ball that measures larger. While hawks have been studied, it has been a fairly limited amount of research fully completed and while my own research is still ongoing and not complete (by my standards) there are regional size differences in most hawk species. There has been more research done and published on Bald Eagles than on any other raptor in the USA.
Our Zoo (as an example) once told me that the Harris Hawk was not found in Arkansas. I have taken them photographic evidence of the family of Harris Hawks that live somewhere in my area. Upon seeing the evidence, they still held to the mistaken belief that the Harris Hawk is not a resident of Arkansas. Unfortunate that "scientist" hold fast to what probably was once true but has changed over time. I remember when the world was thought to be flat. The climate changes that Mother Earth is going through at this time, are changing the habitat ranges of a lot of animals. It will also change what grows in any specific area as rain patterns are currently in flux and not resettling anytime soon. This is "Nature", our mother earth is not stagnate or dead, she is a living being and as such goes through changes as she continues along the great circle, just as all living beings do.