狗狗越小，撒尿时抬腿抬的越高，是装腔作势吗？！狗是最常见的宠物之一，很多朋友家里都养过狗或曾经养过狗。4年前，儿子从老家带回来一只小型土狗，黄白相间的毛发，看起来不算难看。狗狗养成习惯后基本不会在家里大小便，一般是在遛弯的时候解决问题。

气味标记是哺乳动物一种常见的交流模式，狗狗撒尿就有这种作用，也可能是其占有势力范围的一种方式。狗狗很少在没有障碍物的地方撒尿，而是遇到草丛、灌木、树木、路灯柱或石头等才撒尿，目的是在这些物体上留下记号。撒尿时总是把腿高高抬起，我家的狗由于体型想对较小，撒尿时总是把腿抬的老高，直到抬到它自己站站立不稳的角度，我也曾对我家的狗狗撒尿进行了偷拍，不知道狗狗知道后会不会害羞，呵呵；而经常也发现邻居养的大型犬撒尿的时腿反而抬的不是很高。不同体型的狗狗撒尿时抬腿的高度是否差异，估计很多人不知道，最近这个疑问总算有了答案，呵呵。因为有研究者对这个问题进行了系统研究，并在Journal of Zoology期刊上发表了相关研究结果，论文标题为Urine marking in male domestic dogs: honest or dishonest?估计是该研究比较有趣，Science News也对研究结果进行了跟踪报道。

研究人员首先对狗狗撒尿的高度和抬腿角度进行了研究，二者明显存在正相关关系，即狗狗腿抬的越高，尿撒的位置也就越高，因此可以用抬腿的角度来反映尿洒向的角度（the angle between a dog’s raised leg and the axis normal to the ground) is a proxy for urine mark height）。对45只狗进行了撒尿时抬腿角度的测量后发现平均的尿尿角度从约85°到147°，体型大小和尿尿时候抬腿角度呈现明显负相关（significant positive relationships between both raised‐leg angle and height of urine mark and body size (using either body mass or height at withers) and height of urine mark），即体型较小的狗狗在撒尿时往往将腿抬得更高（且体型越小，角度越大），而体型越大的狗狗抬腿角度越小。研究人员认为体型小的狗狗这种行为是试图掩盖其体型的真正大小（Smaller dogs may hoist their legs higher in an attempt to lie about their body size），体型小的狗把尿撒在更高的位置可能会让其他狗狗认为有大型犬在附近，以便独占地盘，呵呵（以下图片引自论文原文）。具体报道见论文原文https://zslpublications.onlinelibrary.wiley.com/doi/full/10.1111/jzo.12603。

Science News原文网址如下（http://www.sciencemag.org/news/2018/08/your-dog-lying-other-dogs-about-its-size）：Is your dog lying to other dogs about its size？

Don't mess with me! That’s the signal small dogs seem to be sending when they pee on things, according to a new study. Researchers have found that the smaller a pooch is, the higher it lifts its leg to mark lamp posts, trees, and other objects—and these exaggerated urine streams may fool other dogs into thinking a large canine is in the area.

 “This paper is important because it looks at a neglected aspect of scent marking,” Lynda Sharpe, an ecologist at Australian National University in Canberra, wrote in an email. Sharpe, who was not involved with the work, has studied dwarf mongooses that leave scent marks from their anal glands by doing handstands; she found that small males leave deceptively high marks. It makes sense that dogs would do the same thing, she says. “It would be surprising if numerous species weren’t exploiting the height of scent marks.”

Conducting the study wasn’t easy. Betty McGuire, a behavioral ecologist at Cornell University, and her colleagues studied 45 dogs from two shelters in New York. The animals, mostly mixed breeds, were all adult males, because they’re more likely to lift their legs when they pee. The researchers walked them outdoors in areas that included trees, benches, a fire hydrant, and other tempting targets, while recording from behind with an iPhone. Precisely measuring pee spots before they dried—without disrupting the dogs midstream—was a challenge. And whereas some dogs liked to mark trees and poles, others preferred tall grass, where their urine was much harder to find. Some dogs, after sniffing a spot and lifting a leg, missed their targets entirely.

“We spent an inordinate amount of time out there,” McGuire says.When a dog made a mark, the researchers measured its height, and then measured the angle of the dog’s raised leg from the video. In all, the team analyzed several hundred leg lifts over about 2 years. The dogs’ average urination angles, which ranged from about 85° to 147°, got more extreme as the animals got smaller, the team reports in the Journal of Zoology.

Smaller dogs may hoist their legs higher in an attempt to lie about their body size. By exaggerating their own bulk, McGuire says, they could be sending a message to the other dogs: “Stay away from me!” The small dogs may hope to avoid face-to-face interactions with other animals likely to outmatch them in a fight.

Still, the dogs may not be lying at all, but instead “overmarking,” says James Serpell, an ethologist at the University of Pennsylvania School of Veterinary Medicine. Dogs often like to cover up other dogs’ pee with their own, he says. Small dogs may lift their legs higher simply because they’re trying to reach a larger dog’s urine spots. Alternately, Serpell says, the explanation might be as simple as anatomy. Maybe all male dogs lift their legs as high as possible to pee, but small dogs are more limbe.