Crossbred Dog - Genetics

Genetics

Hybridization to take advantage of the increased chance that a recessive detrimental allele will only be inherited from one parent, and therefore not expressed in the phenotype of the offspring, is only one strategy breeders can use to decrease the incidences of genetic defects. Knowing the disease incidence in the breed, and the genetic history of the individual, is ultimately important in dog breeding. Having the parental dogs genetically tested for defects known to be troublesome to their breed (or breeds, in the case of mixed parentage) may do as much, or more, than simply choosing dissimilar individuals with functional reproductive tracts. Genetic health must be approached from many angles. However, few who breed "hybrid" dogs do so with any consideration for the actual genetics, as many heritable conditions are conditions of dogs in general, not breed specific. It is a mistaken idea that mixed breed dogs are healthier simply by being mixes.

Because some traits are dominant, crossbreed dogs tend to manifest some physical characteristics more frequently than others. Border Collies and some Spaniels, for example, often produce crossbreed offspring with similar coats and ears. The crossbreed offspring of German Shepherds often have characteristic Shepherd faces. But all crossbred dogs will vary in which characteristics of their purebred parents that they inherit, and may look very different from one another, even within the same litter of puppies.