This page gives guidelines for Animal Breeding which are consistent with the rest of our beliefs and our goals. These guidelines can apply to breeding animals for any purpose, such as for pets, agriculture, re-population of wild populations, or any other purposes.
The goals of these guidelines are to prevent unnecessary animal suffering and to minimize medical or veterinary costs associated with health problems caused by poor breeding.
Guidelines for animal breeding
- Maintain a healthy level of genetic diversity.
- Avoid breeding any aesthetic traits into an animal that come at the expense of causing health problems or other practical problems.
- Avoid focusing on selecting or breeding in any attribute or attributes at the expense of creating other problems. I.e. address the weakest links or problem traits in an animal in addition to working to further develop desired characteristics.
- Let animals choose their own mates; select for traits by adding or removing animals from the pool of available mates, rather than by forcing specific pairings.
Why? What can go wrong in animal breeding?
- Inbreeding, the breeding of closely related animals, or on a broader scale, the isolation of a small population of animals in breeding, can increase the likelihood of various genetic defects caused by recessive genes. Low genetic diversity also leads to a less fit population in the long run. The result is a myriad of health problems which can cause suffering to the animals, and can require costly health care and/or result in animals dying earlier than those from healthy populations.
- Selective breeding to choose specific traits can directly result in health problems. As an example, the Pug, a breed of dog, has been selectively bred for a specific flattened, wrinkled nose and face. This structure to the face, very different from the natural structure of a dog's face, results in increased likelihood of eye injuries, breathing problems, problems regulating body temperature, and infections of the folds of skin.
- Even if genetic diversity is maintained, if the animals are not selected for overall health or for the elimination of weakest or most problematic traits, these traits will persist in a population. For example, if all animals are treated for a condition that would normally result in death, and these treated animals are used for breeding, animals with this condition will persist in the population, making the population dependent on veterinary care, and increasing the costs for caring for these animals in the long-run.
- Humans can make worse choices, from the perspective of health, for selecting individual animals to breed than the animals would. Most animals have evolved complex mate-selection rituals or practices, which assess the fitness of the mate. In nature, animals are more likely to select a mate that is not only healthier overall, but that is a particularly good match to them. For example, there is evidence that humans are more attracted to the smell of humans who have complementary immune system proteins, thus making inbreeding less likely, and increasing the likelihood that offspring will have healthy immune systems. When humans select individual pairings of animals for breeding and remove all choice from the animals, they turn off a natural mechanism that exists in these animals, to prevent inbreeding and keep populations healthy.