Dog shows can be one of the best spots to meet handlers and breeders of Fox Terriers. There are rarely that many breeders in such close proximity. This is a good chance to see who has puppies or will have puppies and which breeder you may wish to buy from. Most breeders at shows are reputable. Sadly, not all are professional and reputable. By talking to various breeders at the show you will quickly learn who to buy from and who not to.
This is a good time to impress the breeders to encourage them to sell to you so don't break the show etiquette rules.
First Rule. Breeders and handlers spend ALOT of time grooming dogs before a show. They are usually very busy before their dogs enter the ring. Do not bother them or touch their dogs before they enter the ring. Many of the dogs leaving the ring will still be shown later so once again, wait until the judging of their dogs are over.
A wire fox terrier in show coat has hundreds of hours of work on that coat. Never pet a dog unless the handler says that it is OK. Chances are if the dog is being shown later that day it is NOT OK. If a handler says that it is OK, pet the dog in the direction that the coat is growing. Never rub the dog of fluff up its coat. Remember, these dogs have hundreds of hours of work in their coats. You will not make any friends if you fluff the coat.
Second, ask them when a good time to talk to them will be. Let them tell you when it is convenient for them. They could be showing multiple breeds in multiple rings. Shows are hectic and confusing. Handlers do not need any additional confusion until the show is over and they will be more willing to spend the time with you.