If you are anything like me, planning for Mother’s Day can be like planning for a future litter of puppies. Caught up in the whirlwind of life, work, fun, kids and family, sometimes the important planning that goes into celebrating our mom or getting our prospective canine mothers prepped for their 9-week puppy rearing adventure, slips to the bottom of the “to do” list.
Luckily, most human moms are easy to please if we simply make a small effort to show that we care. An eleventh hour bouquet of flowers or a last minute lunch date is often enough to let mom know that she really matters, despite our procrastination. Unfortunately for the canine mothers in our life, procrastination in regards to planning a new dam’s first litter, can mean the difference between a healthy group of puppies and a sickly one. In addition to setting aside the time for veterinary health clearances of the heart, eyes, hips, and elbows, genetic testing of a new potential dam (or sire, for that matter) is of utmost importance to puppy health and the reputation of your breeding program. Unfortunately, accidentally putting off genetic testing until your dam is fully ready to breed, may put you in a position to choose between a risky, uninformed breeding or waiting until the next heat cycle and losing the opportunity. Planning ahead in terms of health testing can make the first breeding experience much less chaotic when the future dam of your kennel begins showing the signs that it’s time.
It isn’t uncommon for mothers to withhold information from their children. Whether they made poor decisions they’d rather not discuss or have an insight that might be more appropriate at a later age, human moms try to give the information most critical for their children’s future while treading lightly on the information their little ones may not be ready to hear. Unfortunately, dog mothers aren't quite as good with their secrets. Though they may not have a story of misspent youth to share at a later date, canine mothers are all too willing to share their genetic problems with their future offspring. Luckily, through the use of genetic testing technologies, we can uncover some of the genetic secrets our prospective dams may hold and make sure they do the best they can for their offspring! Two particular groups of inherited diseases are most problematic for breeders; recessive genetic diseases and those inherited diseases which don’t present until later in life.
Recessive Genetic Diseases
The way that a particular disease is inherited plays an important role in prevention. Inherited diseases known as recessive diseases (e.g. progressive retinal atrophy, progressive rod-cone degeneration) are some of the most difficult to control without implementation of genetic testing in a kennel. Recessive genetic diseases are those in which dogs must inherit two copies of the associated genetic mutation (one from each parent) in order to actually develop the condition. Dogs only inheriting a single copy of these mutations are considered carriers of the disease and will not show clinical signs of the condition themselves. However, when bred with another carrier of the same genetic mutation, about 25% of the puppies will either be born with disease or will be at increased risk for the disease as they age.
On a side note, dogs which are closely related are more likely to share the same disease-causing genetic mutations. Therefore, breeding of dogs which are close relatives increases the chance of recessive diseases in their offspring. It is for this reason that breeding of close relatives has often been discouraged by dog breeding experts. Since there are many more unknown disease-causing mutations than those that have been discovered, even with genetic testing, it may not be possible to completely avoid producing puppies with recessive diseases when using closely related breeding pairs.
Late-onset Inherited Diseases
Aside from the way a disease is inherited, the age at which a disease begins to manifest can also cause some difficulties for dog breeders. This is particularly true for those diseases with a late age of onset (e.g. degenerative myelopathy). Dogs with these conditions may be bred many times before ever showing clinical signs of disease themselves. While reputable breeders would rarely have a reason to breed a dog known to be affected with an inherited disease, without testing they might unknowingly facilitate the transmission of late-onset inherited diseases to the puppies in their kennel. To complicate matters further, these diseases may present in a dog’s twilight years when an owner would normally expect to see some signs of slowing down. Owners failing to recognize that the disease affecting their dog is actually an inherited condition may not be inclined to contact their breeder to give them this useful information (assuming they still know how to contact the breeder after all those years).
Performing genetic testing for late-onset inherited diseases holds similar benefits to testing for recessive diseases by uncovering disease-causing mutations present in apparently healthy dogs.
Don’t Forget About Dad
Despite our focus on moms this time of year, it is important to realize that 50% of a puppy’s genetic makeup comes from their sire. Therefore, in order to make appropriate, fully informed breeding decisions, all potential sires should also be tested for inherited diseases prior to breeding. By testing both prospective parents for diseases known to affect the breed and using informed, selective breeding practices, complete prevention of these diseases can be accomplished in a blood line.
Test Parents to Maximize Health and Decrease Future Costs
To maximize the genetic health of your kennel, it is recommended to test all new, incoming dams and sires for all genetic diseases available for testing. At Paw Print Genetics, this can be accomplished by searching for tests by breed and ordering a full breed panel. Since you may not know what diseases could be lurking around in your new dog’s blood line, this approach will inform you about potential issues you could be bringing in to your kennel before you have trouble. In the long run, panel testing all prospective dams and sires prior to breeding serves to improve the overall genetic health of your kennel while decreasing future costs of testing puppies. Using this testing strategy, puppies only need to be tested for the mutations that are found in the parents. You can rest assured that if both parents have normal copies of any given gene, their puppies will as well.
If you have questions about how to prevent inherited disease in your kennel or would like to have any other burning genetics questions answered, please feel free to email the Paw Print Genetics laboratory (AskUs@pawprintgenetics.com) or give us a call (M-F; 8 am to 5 pm PST) at 509-483-5950.