Yes, I have seen many deer on Prestwick St Cuthberts golf course that backs on to runway 21/03. They probably go under the fence rather than over although deer can jump incredible heights.
My friend hit a deer this morning on the A77 and I saw a dead one at the side of the road on the A77 the other day. Scotland is crawling with deer and an official cull to control their numbers is likely soon.
Incidentally if a deer is found within the boundary fence at PIK or indeed any other airfield the directive is to get a suitably qualified and licensed person out to shoot it rather than capturing it and releasing it back to the wild. Don't want o take the chance of it returning again.