Why do dogs eat poop?
ASK A RESEARCHER: Many animals eat faeces; dogs are one example.
Since dogs started living with humans thousands of years ago, they have had free access to all our leftovers, garbage, and faeces from ourselves and our other domestic animals.
Consequently, some researchers believe that at some point, it became more common for dogs to eat faeces.
“It’s obviously very disgusting for us humans when we experience it. We don't think of it as food,” Øystein Ahlstrøm says.
He is a professor at the Norwegian University of Life Sciences (NBMU) and knows a lot about what animals eat. He says that no specific research has been done on exactly why dogs eat poop, but experts have some theories.
Nutrition in poop
Eating faeces is called coprophagy, and many animals do it.
It is common for dogs to do it, and often they eat the faeces of ruminants like horses. It can contain nutrients such as B vitamins.
Dogs also eat faeces from other dogs, cats, and from us humans. The mother of puppies often also eats the faeces of her puppies.
The smell of urine and faeces is a significant part of a dog’s life and can inform them a lot about other dogs in the area. Dogs also use their urine to mark territories, signalling to other dogs that they have been there.
“If they eat faeces from other dogs, they can contract diseases, but based on what we know, it’s not a problem or dangerous for the dog,” Ahlstrøm says.
Not all animals
Dogs like to eat things that have already been digested by another animal. They may also like to eat things that are partially decomposed like peat and soil.
Sometimes dogs also bury food to store it and later dig it up before eating.
“It’s not common for dogs to eat their own faeces, but some dogs do,” Ahlstrøm says.
This could be because they are not getting enough food or are bored.
Ahlstrøm explains that not all animals eat faeces. Cats, for instance, do not. Cats also won’t eat food that has spoiled and is starting to decompose. Instead, they prefer to hunt animals and eat them immediately.
Moose, hare, and hamster
Last year, for the first time, researchers observed a moose eating its own faeces. This was reported on sciencenorway.no.
In the article, we spoke with researcher Christer Moe Rolandsen. He explained that many animals eat faeces.
“For example, hares do this to be able to digest more of the nutrients in the plants they eat,” Rolandsen said.
Hamsters, guinea pigs, and rabbits also eat poop.
Elephant and hippopotamus calves consume faeces from their mothers or other herd animals, possible to ingest essential gut bacteria.
Researchers have seen horses engage in this behaviour as well.
Translated by Alette Bjordal Gjellesvik