You need to jab the bitch 10-14 day before they come into season, so only any good for bitches that are regular.
If you do not wish to breed from the bitch get her spayed, it can also prevent heath problems in the future.
Get him over the field with a tennis ball and make it as fun as ya can.
A lot of young collie crosses can be very annoying doing this (catching with there feet) if he will not entertain the tennis ball bring him ferreting, he will learn, it just might be 10 rabbits before the penny drops, but it could also take double that so the more he sees the better.
Edited to add IF HE HAS NEVER HAD FUR IN HIS MOUTH, GET A SKIN ON A FLERT STICK
Good luck
I can't see how teething can make cartilage go soft, people say is the dog teething, if yes, this is a time when the dog is going through a major growth spurt, rather than making ears/cartilage to go soft, but ha I could be wrong
If your dogs are really bad with fireworks.
Try and get some 5mg valium tablets, and break in two (2.5mg) for a medium size lurcher, and half that (a quarter) for a terrier.