1). Depending on where the Sellers live there are laws as to how many animals in each County a person can have. Ask if the Seller has a Kennel Lic to be able to own the dogs and sell the puppies.. My County allows 5 dogs.. After that you must have a License to own your dogs and the County will tell you how many you can have.. Ask to see it..
2) If doing business ( even one litter a year) the Seller must have a State Business License and possibly a County License . If they do not have this displayed on the wall for you to see then run , don't walk from there.. They are not a business and have only their word for you to depend on. They are a Backyard Breeder without the license.
3) This one is a personal choice but ask if the dogs are AKC Registered. Your males should be DNA after they sire 3 litters and we do ours as babies instead of waiting.. AKC does inspections and this also protects the consumer.. A breeder with AKC has to be responsible and can get caught if they lie on the dogs registration.. We only work with Chihuahuas and all of them are AKC Registered.
4) I wish you well and that you find the "perfect " fur baby you decide on.