You do not need to understand all the intricacies of gene theory or care that scientists are scrambling to map the entire Dog Genome.
What you do need to know is that a dog's genetic makeup determines who and what he is. Genes are the building blocks of life. Each gene serves a function, and carries a blueprint that dictates a whole host of factors ranging from the color of a dog's fur, to how tall it will grow and what 'breed' it is. Genetics can also influence things like temperament. More important, genetics influence whether your dog will be born with certain defects or if they will be susceptible to various ailments, like an immune deficiency.
To complicate matters, should be aware how genes are passed down from one generation to the next.
Each cell contains two sets of duplicate genes, one donated by the mother and one by the father. For example, take a cell that contains information on how a dog's tail will form. Inside this cell are two duplicate sets of genes that hold blueprints for making a tail. If both sets are the same, then there is no problem. If both genes say straight, than the tail will be straight. However, if the pairs are different, than whether that puppy's tail will be straight or curly will depend upon which set is dominate.
Ignoring mutations, you can have several combinations of tail genes: curly-curly, straight-straight, or curly-straight. In some family lines, the curly gene may be dominate, such as in Keeshonds, in others it may be the straight gene that is dominate.
Recessive genes may skip one or more generations. Therefore, you may have two dogs with curly tails that came from parents with curly tails. Yet, when you breed them, they produce a puppy with a straight tail. Why? Because somewhere, hidden deep within their genetic history, both of the puppy's parents had a relative with the gene for a straight tail.
Genetic Diseases
If genetics only dictated color and size, it may not be something to be overly concerned about. However, just as the trait for curly tails may be passed from on generation to the next, so can diseases. For example, hip dysplasia, a joint disease that can lead to severe arthritis in dogs, is a genetic abnormality.
When you begin to consider breeding your dog, you need to think about the genetic implications of your actions. Although your pet may be healthy, if there is a known defect in its pedigree it may be a carrier of that defect and by breeding it may only serve to pass that trait onto the offspring.
Science to the Rescue
In the near future, it will be possible to take a single cell from a dog and actually read its gene structure. At that point, scientists will be able to tell if a given dog carries the gene for hip dysplasia or cataracts or if he will have a good sense of smell. They will be able to read the 'recipe' from which the dog was made.
In the meantime, some medical tests do exist for diagnosing various genetic abnormalities.
For example, hip dysplasia can often be detected by x-raying the dog.
Selecting a Dog
When you begin looking for a new dog, you should be aware that some breeds are known for having specific genetic defects.
In purebreds, especially, this is often caused by poor breeding practices like consistent inbreeding.
Here is a sampling of some known genetic defects associated with a specific breed:
The list is endless. When seeking a new dog, thoroughly research the breed that you are interested in. Research may not prevent you from getting a dog with a genetic disease, but it will make you aware of possible problems – both before and after you get your dog.
