This article is courtesy of AKC Canine Health Foundation.
Whether you buy a puppy or adult, or acquire your new dog from a breeder or a shelter, you want your dog to be as healthy as it can be. And even if you're taking on the responsibility of dog with special needs, you'll want to know ahead of time what you're getting into. Talk to your veterinarian, members of the parent breed club, or rescue groups beforehand -- and then give your dog the best of care for the healthiest life he can have.
"At least you have your health..." That saying is as true for dogs as it is for people. Your dog may be a candidate for an ugly dog contest, may scoff at the idea of fetching a ball, and may be an obedience school dropout, but as long as he has his health, you're ahead of the game. But with all the hoopla about hereditary diseases in purebred dogs, how do you find a healthy dog? No dog is without threat of health disorders. The trick is to decrease that threat. So no matter what kind of dog you're looking for, you need to be a savvy health consumer.
What Causes Hereditary Health Problems?
Some people think the best bet is to get a mixed breed. Pure breeds arose through limiting the gene pool of populations of similar dogs; unfortunately, in a population with a small gene pool, the chances of identical recessive genes (those that take two copies to express themselves) pairing up in one dog are increased. Although this chance may be lessened in some first generation crosses between two breeds, many such recessive genes are so widespread among breeds that crossing breeds is no guarantee they will not pair up in the offspring. And unfortunately, such pairings sometimes cause health problems.
Because inbreeding can increase the chance of recessive bad genes pairing up in the same dog, it's generally a good idea to prefer a puppy from parents that are not closely related to one another. Some online pedigree programs will compute a Coefficient of Inbreeding (COI) for a pedigree; geneticists advise staying under a 10 percent COI for a 10-generation pedigree for best health. However, this is a rough generalization; inbred dogs have lived long healthy lives, just as non-inbred dogs can have hereditary health problems.
Sometimes certain traits that are desirable in some breeds increase the chance of certain health problems. For example, the flat faces of some breeds may predispose them to breathing difficulties. Large or heavy breeds tend to be susceptible to hip dysplasia, and toy breeds to knee problems. Unfortunately, these same problems can occur in all flat-faced, large, or toy-sized dogs, whether pure or mixed. In general, avoiding extremes in body type or any exaggerated features, such as giant size, long backs, droopy skin, or bulging eyes should lessen the chance of some disorders.
"Shots and wormed" was once the gold standard when shopping for a healthy puppy, but these days it's just the baseline. Depending on breed, DNA tests, blood tests, eye examinations, or radiographs might be expected of conscientious breeders before even mating two dogs. In some other breeds, specialized tests might be standard for each puppy before allowing it to go to a new home. When a breeder says puppies have been "health tested" make sure to get a list of what tests are covered; in many cases, it simply means the puppy has been examined by a veterinarian for parasites and other obvious conditions, not tested for breed-specific problems.
Breed-specific health tests: Just what tests you want depends on what breed you're looking at. For example, you'd ideally want a hearing test (preferably a BAER, or brainstem auditory evoked response) in a Dalmatian puppy (and its parents), a hip dysplasia test in Golden Retriever parents, and a DNA test for progressive retinal atrophy (PRA) in a Miniature Poodle puppy or its parents. But you'd expect none of those in a Greyhound. This doesn't mean the Greyhound is necessarily a healthier breed; just that its breed-related health concerns don't yet have reliable screening tests.
The easiest way to find out what tests are desirable for your breed is to go to the Canine Health Information Center (CHIC) to see if your breed is a "CHIC breed." CHIC breeds' parent clubs have agreed upon health screening tests they feel all breeding stock in their breed should undergo before producing a litter. Also check the national parent club website for any additional information on recommended tests and how to understand the results. The Orthopedic Foundation for Animals maintains statistics and databases for several hereditary disorders; check their website (www.offa.org) to see if your breed ranks high for a particular disorder.
Phenotype tests: Some tests are based on the dog's phenotype; that is, any signs the dog may show. These include joint radiographs, eye examinations, blood tests, cardiac examinations, hearing tests, and even MRIs, among others. Some of these tests can be fairly expensive, and the price of a puppy from tested parents will often reflect that added expense. In most cases, normal phenotypic test results of the parents cannot guarantee your puppy will be clear of the disease, but they will greatly increase the odds.
DNA tests: Genotype, or DNA, tests usually give more definitive results. They are available for a growing list of diseases in different breeds. In some cases, DNA tests allow a dog who is affected or is a carrier of a recessive disorder to be bred to a dog that does not carry the disorder and be assured of producing unaffected puppies.