A team of researchers from the United States and Spain have discovered that the domestication of canines might not be healthy after all. Researchers found that domestication leads to an increase in detrimental changes in dogs by using a genome analysis of wolves, wild dogs and domesticated dogs in the hopes of raising awareness of these potential damaging genetic changes in domesticated animals, as explored in a news release.

Although the domestication of canines has been common for roughly 15,000 years and stemmed from the co-mingling of wolves with human populations, many in the scientific field have suspected negative genetic effects due to this relationship and the new findings are the first the confirm these suspicions.

The scientists gathered data from genome samples of 25 semi-feral dogs that originated from ten different countries along with genomic data from 19 gray wolves and 45 breed dogs; these breed dogs covered a wide range of domesticated dog breeds. Using this data, they analyzed all of the genetic variations between the groups, with a focus on deleterious alleles considered "unnatural."

The results showed that domesticated dogs are less able to reproduce and more prone to ailments such as asthma, cancers, eye diseases and arthritis. The researchers suggest an increased population diversity as a solution to the problem as it would allow negative traits to disappear on their own, as opposed to selective breeding programs that consist of small populations and are thus more at risk of harm.

The study was released in the journal Proceedings of the National Academy of Sciences.