狗狗毛色不簡單

狗狗的毛色可能和其健康有關——起碼對于全球最受歡迎的寵物之一來說是這樣的。

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.

根據(jù)一篇于10月21日發(fā)表在《犬類遺傳學和流行病學》雜志上的新研究文章，相較于黑色或黃色的拉布拉多犬來說，巧克力色的拉布拉多壽命更短，而且有著更高患皮膚病和耳部疾病的幾率。

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，一支研究者國際團隊調查了超2000只生活在英國的拉布拉多犬的數(shù)據(jù)。這些數(shù)據(jù)是作為一個名為“獸醫(yī)指南針”的研究項目的一部分而收集的，該研究項目為悉尼大學和倫敦大學皇家獸醫(yī)學院的合作項目。這個大約2000只拉布拉多犬的研究組是隨機從一個含有超過33000只拉布拉多犬的更大的數(shù)據(jù)集中隨機抽取的。

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.

研究人員發(fā)現(xiàn)，在他們所研究的狗狗樣本集中，耳部疾病和皮膚疾病的發(fā)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.

比如說，一種名為膿性創(chuàng)傷性皮膚炎(pyotraumatic dermatitis)的狗狗常見皮膚感染——更常被稱為“熱斑”——在巧克力色拉布拉多身上的發(fā)病率是黑色和黃色同類的兩倍還多。同樣的，外耳炎這種耳道感染在巧克力色的拉布拉多身上更常見。

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們的壽命相關。研究人員發(fā)現(xiàn)，非巧克力色的拉布拉多犬在英國的平均壽命為12年，而巧克力色的拉布拉多犬平均壽命只有10.7年，低了超過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.

研究人員指出這些關聯(lián)之間的原因——狗狗毛色和健康之間——仍是未知數(shù)。的確，該研究文章中作者也寫道，這一發(fā)現(xiàn)“值得更進一步的研究調查”。

However, genetics plays a role, the researchers said.

不過，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.

“毛色和疾病之間的關系可能反映出了刻意繁殖出特定毛色狗狗的無意后果，”該研究文章的第一作者、來自悉尼大學的獸醫(yī)科學教授Paul McGreevy在聲明中說道。

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).

狗狗毛色這樣的特征由兩個基因組合所主導：一個來自母親而另一個來自父親。這種基因可以是“顯性的”也可以是“隱性的”。拉布拉多的巧克力色是由隱性基因主導;這就意味著狗狗必須從雙親那里都繼承一條巧克力色的基因才能有這樣的毛色。(如果這種基因是顯性基因，狗狗只需要一個基因)

"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.

“因此想要繁育出這種毛色的人更有可能只繁育那些攜帶巧克力毛色基因的拉布拉多，”McGreevy說道。根據(jù)該研究，這限制了基因庫的規(guī)模，而基因庫規(guī)模越小的狗狗，或許越容易出現(xiàn)皮膚和耳部問題，也就是說它們也更容易將這些問題遺傳給自己的孩子們。

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.

還不清楚在其他品種的狗狗里，或者是世界上其他地區(qū)的拉布拉多中是否也是如此。目前，研究人員正在為澳洲的拉布拉多進行一場類似的研究。