Thrusting rather than chopping might be more effective and safer for the dog. Pitiful little cat; I doubt it weighed over thirty-five pounds. Chocolate lab wasn't much help.
Last one I shot here was behind the corral in a tree and was about three times the size of this one. I was uphill from the tree so the cat was on my level and about fifteen feet away. I used a Model 94, 30/30. At the shot, the cat went over my right shoulder and hit the ground thrashing, The big dog, a pit/labX was on the cat immediately while Beagle Bailley bayed moral support from a safe distance. I would rather have more predators here and fewer people, quite frankly. GD