My wife and I currently have two dogs, but our more recent (which we picked up 7 years ago) is a dachshund named Wes. Before we picked him up, we would regularly swing by the pet store on Davis to check out the dogs, cats, snakes, fish, etc. We never intended to purchase a dog from a pet store like that, and I do not recommend that anyone do that to this day. But we nevertheless would stop by because we liked checking them out. One day we saw this weird looking dog that neither of us could identify. I decided to ask an employee what the breed was. "It's a wire haired double dapple dachshund". Sounded like BS to me. The girl asked us if we wanted to visit with the dog in one of those rooms where people go who are interested in purchasing. Absolutely not! We don't buy dogs from pet stores. But the girl insisted that we would be doing the dog a favor. It would give him a chance to get out of his cage and get petted. Fair enough. So we're in the room with the dog and I start to wonder, "How much do they want for him?" - only out of curiosity of course. I almost died laughing when they told us. 15 minutes later we're driving home with him on my lap.
I was still not convinced about the "wire haired double dapple dachshund" BS, so I did some research. It turned out that double dapples are an inhumane version of a dachshund to breed, because out of each litter there is a high probability of getting dogs that are blind, deaf, both, or worse. But you will get at least one dog with a highly desirable, unique looking coat. Had my wife and I known this, we would not have purchased this dog, but he is nevertheless the best dog we have ever had. Learning that about our dog Wes led us to do extensive research on the dachshund breed, and we are now somewhat of experts on the types of coats, colors, sizes, etc that are available for dachshunds - what is humane and what isn't humane. Etc. But, point being, there are certainly unethical breeders out there. My wife and I had the alibi of ignorance when we got our dog, but we won't fall prey to that again.
Long story short, never buy dog from a breeder unless you have done some research, and you know for certain that your dog is not the result of unethical breeding practices.