As the world has evolved, so too has the number of animals in the wild. When animals evolve in nature, this process is known as natural selection and only the strong survive as the best genetic information is passed from one generation to the next. However, there is another method of ensuring that a breed has specific characteristics such as size, coloring, behavior patterns, and so on. This is selective breeding, which is a form of artificial evolution.
While this process follows the same concept as natural selection, man gets involved and forces the changes to occur at a different pace--in some cases, the time frame is shorter, in others, it's longer. While selective breeding may result in a "better" dog, it comes with a high risk of many health problems. Here are five common health problems that can occur in dogs that have been selectively bred.
#1. Walking Difficulties
There are several breeds of "pedigree" dogs that are bred specifically for their looks, such as Alaskan Malamutes and German Shepherds, that may end up with walking difficulties due to selective breeding. The most of common of these is hip dysplasia, which is caused by an abnormal formation of the hip joints. Others include elbow dysplasia and chondrodystrophy, which occurs when the cartilage grows and matures at a faster than normal rate.
This condition makes the bones fuse together faster than they would normally, resulting in stunted growth, something that is actually sought after in many breeds. But at the same time, it can result in spinal injuries that are extremely painful and may lead to neurological problems.
#2. Breathing Difficulties
There are a number of breeds with very short muzzles that have difficulty breathing due to what is referred to as brachycephalic airway obstruction syndrome (BAOS). This is caused when the muzzle is very short due to the skull being shortened while the muzzle tissue has not been. This can cause the dog's nostril openings to be much smaller and narrower than they should be. Selective breeding has been used to progressively shorten the muzzle of certain breeds, including the Pug, French Bulldog, and Pekingese.
#3. Birthing Difficulties
There are a number of breeds that face difficulties during the birthing process, to the point at which the only way they can give birth to their puppies is through caesarian section. This typically occurs in dogs that are bred for their big head, wide shoulders, and narrow hips. This combination leads to a condition in which the head and shoulders are too wide for the puppies to pass through the pelvic canal. The Bulldog, with broad shoulders and big chest, is a prime example.
#4. Major Eye Problems
You might be surprised to learn that selective breeding causes a number of very serious eye diseases. Among these are entropion, corneal trauma/ulceration, and progressive retinal atrophy (PRA).
Entropion is a condition in which the eyelids fold inwards, rubbing the surface of the eye and causing irritation and damage. It is very common in dog breeds with wrinkled faces such as the Chinese Shar-Pei, Bulldog, English Mastiff, and Bloodhound. Corneal trauma and ulceration occur when erosion occurs to the outer surface of the dog's eyes. This is common in dogs with shorter muzzles as their eye sockets are shallower, resulting in bulging eyes that are more prone to injury. PRA covers a range of genetic eye diseases that can cause slow retinal degeneration and a loss of vision that ends in blindness.
#5. Severe Skin Issues
There are a number of breeds that are naturally predisposed to severe skin issues, especially those with wrinkles. The Pug and Chinese Shar-Pei are examples. Selective breeding has caused these wrinkles to become more prominent, which can lead to folding, infection, and inflammation. Others, like the Cocker Spaniel, are more prone to skin allergies and ear infections due to elongated ears.
Price of Perfection
Selective breeding may result in more "perfect" breeds according to some, but according to vets it also leads to a number of common medical problems. Choose breeders who practice ethical breeding habits and care more about the health of their puppies than they do about "perfect" looks.