Health Issues

Border Collies are considered to be a generally healthy breed. However, as in all animals, there are some potential health problems. This information is presented to help both breeders and buyers to become more aware of some of the health and genetic issues in the breed at this time.

Copy and paste the following websites in to your browser: www.pawprintsgenetics.com and www.optigen.com and click on the breed tab, and then border collie tab and that will educate you on the various DNA tests available.

Next click on the various tabs underneath the health section tab.

 To be considered a genetic disease, a health problem needs to have been demonstrated to be inheritable, that is, passed on through one or both parents. Some diseases have high heritability, which means if the genes are present, the individual will have the disease, and some diseases have low heritability, meaning both genetic and environmental factors are involved in whether the disease occurs. It is generally easier to control diseases with high heritability because all individuals with the genetic makeup for the disease can usually be identified. The term heritable disease should be distinguished from the term congenital disease, or problems that are present from birth, which may or may not be heritable.

What are inherited genetic diseases?

Inherited genetic diseases are diseases that can be passed from parent to offspring through reproduction. Every dog has two copies of each gene (inherited biological blueprints); one copy from their mother and one from their father. Genes contain the information used to create and maintain cells of the body. Mistakes (known as mutations) that occur in genes can result in disease by disrupting normal processes of creating and maintaining these cells. Nearly every cell in the canine body contains an entire copy of the approximately 20,000 genes that interact with each other to bring about the physical traits that make an individual who they are. Genetic diseases can involve any system of the body and dogs can present with a wide variety of clinical signs depending on the particular gene and organ system involved.

What is a “Carrier” of a Recessive disease?

Recessive inherited diseases are those in which an individual must inherit two copies of a mutated gene (one from each parent) in order to develop the associated condition.

Dogs inheriting two copies of the mutation are typically not recommended for breeding because even if bred to a dog that does not have the same genetic mutation, every puppy from the litter would inherit a single copy of the disease-associated mutation, thereby increasing the frequency of the mutation in the breed population to a significant degree.

Dogs inheriting one copy of the mutation from a single parent are considered “carriers” of the disease and will not develop clinical signs of the disease themselves. However, when bred with another dog which carries the same mutation, approximately 25% of the offspring will inherit two copies of the mutation and will be at risk for or affected with the associated condition.

Therefore, in general, it is recommended to only breed a carrier to a dog which did not inherit the same mutation. Using statistics as a guide, this strategy is expected to result in a litter consisting of approximately 50% carrier offspring and 50% normal or “clear” offspring. Thus, avoiding the removal of the carrier dog and its unique combination of genetic variants that contribute to the overall genetic diversity of the breed while limiting the number of puppies born with the known, disease-associated mutation.