When my parents visit, they like to bring their little dog. She likes to escape from our yard by climbing under the gates. My dad went on a mission over Christmas to dog-proof our yard. The photos pretty much speak for themselves.
After - South Gate
Before - North Gate
After - North Gate
We also shored up both gates because they were sagging a bit. Most importantly, we reconfigured the latch release on the south gate. Instead of a nearly useless string, we drilled a hole thorough the post and installed a wire pull.