If you need to improve your fencing or put new fencing up, the general rule I have heard and seen with deer (the most common menace) is to either do an 8 foot high fence or do a 6 foot fence with another piece on top of it, slanted outward for 2 feet. Deer can jump high OR they can jump wide, they cannot do both at the same time. I'd rather have a dog...cheaper and you can cuddle better with a dog than a fence :)