Why does a dog eat poo?
Technically, eating poop is called coprophagia. If you want to be specific, there are two types. Autocoprophagy is the term used for animals that eat their own faeces, while allocoprophagy is reserved for those that eat the faeces of other animals from the same species. There is also caecotrophy, a fancy name for eating the faeces of another species. So we have the dog who turns immediately to eat their own poop in the garden, usually followed by an eagle-eyed owner ready to scoop it up while it’s still warm. Next is the dog that scavenges for poop left by housemate dogs or other dogs. And we have the dog who loves to eat random poop on walks.
Bemused? Yes, us too! It would be great to be able to allow our dogs out to mooch around the garden or enjoy the sunshine while we get on with chores inside. And allowing them off-lead on walks would be much more relaxing if you didn’t have to worry about what they might be scavenging for in the bushes. While it's suggested that in wild canines, coprophagy helps reduce the incidence of stool-borne parasites around their territory, in pet dogs, it can increase the risk of a worm infestation or even toxicosis from drugs consumed by the dog whose poop they eat.
It’s not about hunger. Dogs will eat poop immediately after a meal or a yummy treat. This can be incredibly demoralising; you may ask yourself what am I doing wrong as an owner that they need to go straight out and eat poop? Isn’t their meal good enough? Chances are, however irritating this behaviour can be, it comes down to our widely-differing perceptions of poop. To us, it’s inconceivable, but a dog perceives poop in a very different way. For them, eating poop just doesn’t hold the same level of disgust it does for us.
Explanations for this habit abound, but the bottom line is that they are still merely best guesses. Coprophagy may be a behaviour established centuries ago, during the evolution of man’s best friend. The ‘scavenger hypothesis’ of domestication proposes that proto-dogs took advantage of a new ecological niche created when our hunter-gatherer ancestors settled down and started creating farming communities. Any permanent settlement is soon going to need a plan to deal with the waste that accumulates, and the associated village dumps became a source of easy food for any wolf brave enough to exploit it. And that meant poop, as well as food waste. Bizarrely, it can be surprisingly nutritious! In some parts of the world, feral dog populations rely on access to human waste for survival, playing a significant role in local sanitary disposal.
A mother dog will lick her pups clean for the first few weeks after birth, stimulating elimination. As a result, she ends up eating the faeces. However, other than this, the motivation for coprophagy is not really understood. Suggestions include anxiety or boredom, insufficient diet, or an overall lack of food. It shows no links to age, neutering status or age at which they left their mother. It’s not learned in early life nor linked to diet. Indeed, it can occur in kennelled dogs, where stress and a lack of enrichment could contribute. Boredom may also be a factor for those home alone for long enough to need to toilet. Once it becomes a habit, the behaviour is likely to reoccur. Research has not shown that being over-or underweight is linked to this behaviour, but owners of coprophagic dogs are more likely to report that they are ‘greedy’.
- Jennifer Dow