中國有句俗語，叫“狗改不了吃屎”，比喻惡習不改，劣性難移。吃屎確實是狗狗的一種天性。但一旦狗狗形成吃大便的習慣，真的會令主人非常困擾（試想像狗狗吃過大便后來親你）。

研究發(fā)現(xiàn)，23％的狗至少吃過一次屎，而某些品種的狗更容易吃糞便，謝德蘭牧犬食糞的概率最高(41％)。

A 2018 study published in the Journal of Veterinary Medicine and Science surveyed about 1,400 dog owners in the United States and found that 23% of dogs had eaten poop at least once and 16% were "frequent" poop eaters who ate poop at least six times over the course of the study.
2018年發(fā)表在《獸醫(yī)學與科學雜志》上的一項研究調查了美國約1400名狗主人，發(fā)現(xiàn)23％的狗至少吃過一次屎，16％的狗在研究期間吃過至少六次。

那么狗真的改不了吃屎嗎？狗為什么要吃屎嗎？該如何阻止這個習慣呢？獸醫(yī)學家們給出了解釋。

狗為什么吃屎，這對它們有害嗎？

Dogs eating their own poop — a condition called coprophagia — is considered a natural behavior. It's not a form of attention seeking or a result of nutritional deficiencies. Instead, veterinarians think coprophagia in dogs stems from their evolutionary connection to wolves, as wolf mothers eat their pups' poop to avoid exposing them to intestinal parasites.
狗吃自己的糞便，被稱為食糞癥，這種行為是一種自然行為。狗吃糞便不是為了尋求關注或缺乏營養(yǎng)。相反，獸醫(yī)認為狗的食糞癥源自它們與狼在基因上的聯(lián)系，因為母狼會吃幼崽的糞便以避免小狼接觸到腸道寄生蟲。

Wolves will eat the feces of their young during the first three years of life, veterinarian Dr. Nicholas Dodman, president of the nonprofit Center for Canine Behavior Studies and a professor emeritus at Tufts University Cummings School of Veterinary Medicine, told Live Science. In fresh poop, the eggs of various parasites are not yet infectious. If let to sit, the parasites can grow and infect the pups if ingested.
獸醫(yī)、非營利性機構“犬行為研究中心”主席、塔夫茨大學醫(yī)學院榮休教授尼古拉斯·多德曼博士告訴《生活科學》，狼在幼崽出生后的三年會吃掉它們的糞便。在新鮮的糞便中，各種寄生蟲的卵還不具傳染性。如果放置一段時間，這些寄生蟲就會生長并在幼崽攝入后感染它們。

"You're more likely to survive if you're healthy than if you're … ridden with worms," he said.
他說：“和身上滿是寄生蟲的小狼相比，健康的小狼更有可能存活下來?！?/p>

Even though domesticated dogs have come a long way from the wolf den, "I think the important takeaway is that it's no risk; it's just disgusting to us because of our upbringing," Dodman said.
盡管馴養(yǎng)的狗已經和狼有很大區(qū)別，但多德曼說，“重要的是，狗吃糞便沒有危害；人類覺得這很惡心是因為我們的認知”。

哪些狗狗吃糞便？

Certain dog breeds might be more prone to coprophagy, the 2018 study found. Shetland sheepdogs had the highest rate of coprophagia (41%), while no poodles were reported as poop-eating. A dog's sex is also linked to its tendency to eat poop. A 2019 study conducted by Dodman and colleagues and published in the Journal of Veterinary Behavior looked at the behavior of over 4,000 dogs. They found 11% of male dogs engaged in poop eating, while 16% of female dogs did. Interestingly, coprographia was twice as common in dogs that were neutered than in dogs that were not neutered.
該研究發(fā)現(xiàn)，某些品種的狗更容易吃糞便。謝德蘭牧犬食糞的概率最高(41％)，而研究稱沒有發(fā)現(xiàn)貴賓犬吃糞便。狗的性別也與其吃糞便的傾向有關。多德曼和同事們于2019年進行的一項研究發(fā)現(xiàn)，在4000多只狗中，11％的公狗會吃大便，而16％的母狗會。有趣的是，絕育的狗食糞的概率是未絕育的狗的兩倍。

As for why dogs eat the poop of other animals, like cats and rabbits … it's just tasty, Melissa Bain, a veterinary behaviorist at UC Davis Veterinary Medicine and co-author of the 2018 study, told Live Science. Cats eat a high-protein diet, so their stool might be particularly delectable to dogs, she said.
至于為什么狗會吃其他動物的屎，比如貓和兔子……它們只是覺得好吃，加州大學戴維斯分校獸醫(yī)行為學家、2018年研究的合著者梅麗莎·貝恩告訴《生活科學》。貓吃高蛋白飲食，所以它們的糞便對狗來說可能特別美味。

該如何讓狗停止吃糞便？

Even if it's not harmful to your pooch, there's no denying that people are repulsed by poop eating. So is there anything you can do to get your dog to stop?
即使吃糞便對你的狗沒有害處，人們也無法否認食糞癥令人反感。那么有沒有辦法讓你的狗停止吃大便呢？

Several commercial products are marketed for getting dogs to stop eating poop, but these have not been proved effective. Bain's 2018 study looked at 11 food additives marketed for coprophagia and found that the effectiveness of these products ranged from zero to 2%. "Don't waste your money," she said.
市場上有幾種產品宣傳可以讓狗停止吃屎，但這些產品的有效性還沒有得到證明。貝恩的2018年研究調查了11種市場上用于治療食糞癥的食品添加劑，發(fā)現(xiàn)這些產品的有效性從零到2％不等。“別浪費你的錢，”她說。

The internet is full of home remedies to stop coprophagia, like adding breath mints or pineapple to a dog's food. But there's no evidence that this works for most dogs, either. "You'll probably find someone who says they think it worked in their dog," Dodman said. "But basically, it's not a strategy that you can rely on."
互聯(lián)網上充斥著阻止狗吃糞便的方法，比如在狗糧中添加薄荷糖或菠蘿。但也沒有證據(jù)表明這對大多數(shù)狗都有效。多德曼說：“你可能會發(fā)現(xiàn)有人說他們認為這對他們的狗有效。但基本上，這不是一種可靠的策略?！?/p>

In his veterinary practice, Dodman has tried diet changes that alter the consistency of a dog's poop and stop coprophagia. 
多德曼在實踐中，嘗試過通過改變狗的飲食，以改變狗糞便的稠度，從而阻止食糞癥。

"If you change it to be less palatable, if you can imagine that, and more … dry and cardboardy, that seems to work," Dodman said, although he has not tested this in clinical trials.
多德曼說：“如果把糞便變得不那么可口，可以想象一下，變得更……干燥粗硬，這似乎是有效的，這似乎是有效的?！北M管他還沒有在臨床試驗中測試過這一點。

What does work? "Clean it up," Bain said, and give the dog no time to munch on its feces. Some owners may try sprinkling Tabasco sauce or cayenne pepper on a dog's poop to deter them from eating it. "But if you're going to do that," Dodman said, "you might as well pick it up."
什么方法最有效？貝恩回答，“把糞便清理干凈”，不給狗吃屎的時間。有的狗主人可能會嘗試在狗屎上撒辣椒醬或辣椒粉。多德曼說： “但如果你要這么做，還不如及時清理?！?/p>