180 degree motion servo that can take a hit
I would approach this as a mechanical problem, not a servo-selection problem. Design a mechanism which can take a hit and keep the servo isolated, then you only need a normally rated servo (one that can move the object, rather than being strong enough to cut a dog in half).

I would look at adding some spring, rubber, a cush-drive, overload or slip clutch (or dog clutch, ha ha!), or just slack in the mechanism to allow the movement/impact.

Personally I'd look closely at other actuation methods, for example small pneumatic cylinders are easily actuated with solenoid valves and a £5 12v car tyre inflator can provide enough air, and being pneumatic they will take having their pistons moved by force and return naturally to where they're set.