You may have heard stories in your high school science classes about kings and queens who used to keep their bloodlines pure by marrying within the family. After years and years of this practice, a child would be born with tons of physical and mental problems. Your teacher probably explained to you that this was because all the “bad” genes eventually came about through inbreeding. Whether this story is true or just an illustration, it makes a valid point, along with a bit of exaggeration. Genetics is a complicated science, so this will be explained as simply as possible.
It is easier to understand playback problems if you can identify the different playback methods. Inbreeding, as demonstrated with kings and queens, is the process of reproduction within the family. That is, the man and the woman are relatives, even if they are only cousins. Inbreeding is a form of inbreeding used to achieve “hard-to-find” traits, such as a recessive color. Inbreeding takes a son or daughter and crosses it with the female. Crossbreeding is a practice where the dogs are of mixed breeds. Advocates of crossbreeding claim that the dogs are much healthier than inbred dogs. Almost everything about the dog is inherited or developed through the environment. Eye color, coat color, size, and temperament are all passed down through breeding. However, temperament can also be affected by the environment in which the puppy is kept.
Even the best breeders can run into problems. Depending on the size of the operation, there will most likely be a small handful of males and females that are used for breeding. Sometimes there are even only two dogs that breed continuously. You may be wondering why a breeder wouldn’t breed two dogs from completely different bloodlines. This can and does happen; but the difficulty arises when the breeder is trying to achieve a desired trait. It is highly unlikely that dogs from two different lineages will have the same trait. This is when inbreeding takes place. If a breeder is trying to produce puppies of a recessive color, he will use line breeding to accomplish his task. However, when reproducing you can’t choose which genes to pass on, and the bad ones are passed along with the good ones (the same goes for inbreeding). Eventually, a genetic disorder arises because, simply put, the bad genes accumulated and affected the bloodline.
Another similar problem occurs when a dog is used to breed multiple litters. For example, people may want a direct descendant of a dog that has won all kinds of competitions and awards. Why not raise it? It’s almost perfect, right? Well, actually, he still carries not-so-good genes that are veiled by the better genes. However, you can bet that it will stream both types.
A good breeder will not use dogs that have known genetic defects to breed more puppies. This is why many breeders will guarantee the health of their puppies. However, an uneducated backyard breeder will continue to produce unhealthy dogs, especially since many of the disorders do not show up until later in life. Hip dysplasia, eye problems, and heart problems are all genetic disorders that have made their way into the bloodlines of the breeds. Not only does this add to pet overpopulation (where many end up being euthanized), but it also adds unhealthy animals to the problem.
Parenting is a science that involves the help and knowledge of many people. Fortunately, breeders do not have to cope with the tasks on their own. There are organizations that help provide breeders with information about certain genetic diseases or defects and the results of recent studies on the two. Keeping an open line of communication between breeders also helps in the breeding process.
There are many problems that can stem from improper breeding, and this just touched the tip of the iceberg. Although it is not easy to understand the hows and whys of gene selection and inheritance, it is beneficial to understand the complications of reproduction. Even the best breeders can run into problems that are simply out of their control (remember the environment can play a big part). Open communication is growing in popularity and helps breeders raise healthy pets.