狗狗的毛色可能和其健康有关——起码对于全球最受欢迎的宠物之一来说是这样的。

Chocolate Labrador retrievers tend to live shorter lives and have a higher rate of skin and ear diseases than their black or yellow-coated peers, according to a new study published yesterday (Oct. 21) in the journal Canine Genetics and Epidemiology.

根据一篇于10月21日发表在《犬类遗传学和流行病学》杂志上的新研究文章，相较于黑色或黄色的拉布拉多犬来说，巧克力色的拉布拉多寿命更短，而且有着更高患皮肤病和耳部疾病的几率。

An international group of researchers examined data from more than 2,000 Labradors living in the U.K. in 2013. The data was collected as a part of research project called VetCompass, a collaboration between the University of Sydney and the Royal Veterinary College at the University of London. The group of around 2,000 Labs was randomly selected from a larger dataset containing more than 33,000 Labrador retrievers.

2013年，一支研究者国际团队调查了超2000只生活在英国的拉布拉多犬的数据。这些数据是作为一个名为“兽医指南针”的研究项目的一部分而收集的，该研究项目为悉尼大学和伦敦大学皇家兽医学院的合作项目。这个大约2000只拉布拉多犬的研究组是随机从一个含有超过33000只拉布拉多犬的更大的数据集中随机抽取的。

The researchers found that, within the sample set of the dogs they studied, the incidence of ear and skin disease was much more prevalent in chocolate Labs than in other Labs.

研究人员发现，在他们所研究的狗狗样本集中，耳部疾病和皮肤疾病的发病率在巧克力色的拉布拉多犬中更普遍。

For example, rates of a common skin infection in dogs called pyotraumatic dermatitis — more commonly known as "hot spots" — were more than twofold higher in chocolate Labs than black and yellow Labs. Similarly, "swimmer's ear," or otitis externa, an infection of the ear canal, also turned up more often in chocolate Labs than in other colored Labs.

比如说，一种名为脓性创伤性皮肤炎(pyotraumatic dermatitis)的狗狗常见皮肤感染——更常被称为“热斑”——在巧克力色拉布拉多身上的发病率是黑色和黄色同类的两倍还多。同样的，外耳炎这种耳道感染在巧克力色的拉布拉多身上更常见。

A Lab's fur color even seemed to be associated with how long the dog lived. The researchers found that non-chocolate Labs lived, on average, 12 years in the U.K., whereas chocolate Labs lived, on average, 10.7 years, a drop of more than 10 percent.

而且拉布拉多的毛色甚至似乎和它们的寿命相关。研究人员发现，非巧克力色的拉布拉多犬在英国的平均寿命为12年，而巧克力色的拉布拉多犬平均寿命只有10.7年，低了超过10%。

The researchers noted that the reason for these links — between fur color and dog health — are still unknown. Indeed, the finding "merits further investigation," the authors wrote in the study.

研究人员指出这些关联之间的原因——狗狗毛色和健康之间——仍是未知数。的确，该研究文章中作者也写道，这一发现“值得更进一步的研究调查”。

However, genetics plays a role, the researchers said.

不过，研究者表示，基因起了一定作用。

"The relationships between coat color and disease may reflect an inadvertent consequence of breeding" dogs to be certain colors, lead author Paul McGreevy, a professor of veterinary science at the University of Sydney and chair of board of VetCompass, said in a statement.

“毛色和疾病之间的关系可能反映出了刻意繁殖出特定毛色狗狗的无意后果，”该研究文章的第一作者、来自悉尼大学的兽医科学教授Paul McGreevy在声明中说道。

A trait like a dog's fur color is dictated by the combination of two genes: one from the mother and one from the father. A gene can either be "recessive" or "dominant." The chocolate color in Labs is coded by recessive genes; this means that the puppies must receive one gene from each parent that codes for the chocolate color in order for the puppy to have chocolate-colored fur. (If the gene was dominant, the puppy would need only one gene to have the trait).

狗狗毛色这样的特征由两个基因组合所主导：一个来自母亲而另一个来自父亲。这种基因可以是“显性的”也可以是“隐性的”。拉布拉多的巧克力色是由隐性基因主导;这就意味着狗狗必须从双亲那里都继承一条巧克力色的基因才能有这样的毛色。(如果这种基因是显性基因，狗狗只需要一个基因)

"Breeders targeting this color may therefore be more likely to breed only Labradors carrying the chocolate coat gene," McGreevy said. This restricts the gene pool, and the dogs in this smaller pool might be more predisposed to skin and ear conditions, which means their puppies are more likely to inherit them, according to the study.

“因此想要繁育出这种毛色的人更有可能只繁育那些携带巧克力毛色基因的拉布拉多，”McGreevy说道。根据该研究，这限制了基因库的规模，而基因库规模越小的狗狗，或许越容易出现皮肤和耳部问题，也就是说它们也更容易将这些问题遗传给自己的孩子们。

It's unclear whether this holds true in other breeds, as well as in Labs around the world. Now, the researchers are conducting a similar study of Labs in Australia.

还不清楚在其他品种的狗狗里，或者是世界上其他地区的拉布拉多中是否也是如此。目前，研究人员正在为澳洲的拉布拉多进行一场类似的研究。