狗狗的鼻子为什么总是湿的？

　　Humans and dogs share a special relationship, moulded over millennia of reciprocal love and companionship.

　　数千年来，人类和狗狗都有十分特殊的关系，相互喜爱，相互陪伴。

　　Anyone who's ever had the fortune of sharing their life with a close canine companion can attest that, from poodles to Pomeranians, dogs truly are a wondrous species.

　　有幸拥有一只狗狗作伴的人，都能证明这一点。无论是卷毛还是博美，狗狗确实是种超赞的物种。

　　狗狗的鼻子为什么总是湿的？

　　But there's something else that dog lovers the world over know all too intimately – the feel of a dog's cool, wet nose brushing up against your cheek.

　　爱狗之人还有个场景再熟悉不过——狗狗爱用湿漉漉、冰凉凉的鼻子，在你的脸上蹭来蹭去。

　　Whether they're running to fetch a ball, or merely pinning you down while they're snoozing on the couch, dogs'noses seem to be perennially wet.

　　无论它们是跑去捡球，还是正在沙发打盹的它们，看到你过来立马激动地把你扑倒，它们的鼻子总是湿湿的。

　　So what gives?

　　这带给我们什么信息呢？

　　To most dog owners, it's common knowledge that dogs don't sweat. Their lack of proper sweat glands, as humans and some other mammals have, is one of the main causes of the excessive panting that happens when your mastiff mate is out for a run. Put simply, panting is a method of regulating heat within the canine body.

　　大多数狗主人都知道狗狗不会排汗的常识。它们没有人类和其他哺乳动物的汗腺，这也是为什么它们跑起来会不停喘气。简单说，喘气是狗狗调节体温的一种方式。

　　One other way which dogs keep cool though, is by excreting a substance similar to sweat on their extremities – namely, their nose and paws.

　　狗狗另一种降低体温的方式，就是在手足部分（鼻子和爪子）分泌类似汗液的液体。

　　Ever wonder why they're a similar colour and texture? Boom. There's your answer. The moisture on their extremities helps to radiate heat away from your pawed pal, in a similar way to their panting.

　　好奇为什么这种液体跟汗液颜色和质感这么相似吗？我们来告诉你答案。它们手足分泌的液体帮助它们散热，跟喘气效果相同。

　　The moisture on a dog's nose helps serve a secondary purpose, too. Covering a canine nose is a thin layer of mucous, which helps to trap scents and other particles in the air.

　　狗狗鼻子上的湿气还有另一个用途。它们鼻子上薄薄一层粘液，能帮助捕捉空气中的气味和微粒。

　　In order to sample this no-doubt delectable melange, a dog will then proceed to lick its nose – a behaviour dog lovers will no doubt have noticed when their precious pup picks up a scent. This serves to present the trapped particles to the olfactory glands on the roof of a dog's mouth, enabling the dog to further analyse the scent.

　　为了检验这些味道，狗狗会去舔自己的鼻子。当心爱的狗狗嗅到气味时，爱狗之人对它们以上的举止一定不会陌生。这个举止能让把鼻子上收集到的颗粒送到口腔顶部的嗅腺，让它们能进一步分析这种味道。