Dogs (and bitches ) will sometimes move Heaven & Earth to get to each other, so do keep an eye that they don't dig under the fence or climb over. Dogs have been known to mate through chain link fences.
The average bitch will be most receptive between 10-14 days, but there is the odd exception that will conceive the first week of their heat & some will not stand to be mated until about 20 days.
Poor Leo, this is like putting a glass of water just out of reach of a man dying of dehydration.
Cavaliers......Tommy Tuppence 2000-2012 and a half share of Faith.
Japanese Chins.... Dandy, Benny, Bridgette and Hana.