There are, of course, cats as large as German Shepherds – therefore physically capable of this feat.
However, such a cat is more likely to drag a person 50 yards away from the highway in order to enjoy an undisturbed meal.
Update 5:02PM : I did not forget about large canine predators in the wild. I’ve heard of Wolves. I understand I’m comparing domesticated canines to undomesticated felines.
The point being that, aside from the fact Paris Hilton couldn’t carry one in her handbag, there are reasons we haven’t domesticated even Felis rufus at 20 pounds.
Next up would be Lynx canadensis topping out at maybe 40 pounds.
Comparable in weight to a Shepherd, we have the 90 – 150 pound Felis concolor.
“Nice kitty. How about a treat?! …….SIT! SIT!! …………………SH*T…”