Theories abound: They’re bored; they have enzyme deficiencies; it’s a problem with the pancreas; they do it for attention (if so, it’s working, but maybe not the way they were hoping); they like the taste (ugh); and, most annoying of all, they’re just really, really, hungry.
But so far, there hasn’t been a lot of convincing evidence for any of these answers. Now, new research suggests that dogs might eat their own poop for the most counter-intuitive of reasons:
To keep from getting sick.
Technically, eating feces is called coprophagy, and it’s normal behavior among many animals. According to the survey, 16% of dogs regularly eat feces, either their own or another animal’s. And while eating feces isn’t necessarily good for dogs, it isn’t necessarily harmful either. The biggest problem with coprophagy is that people get upset by it.
Research has discovered that coprophagous dogs were much more likely to be “greedy eaters.” They were more likely to be found in multidog households, where you would also expect to find a greater concentration of stools, i.e., more targets of opportunity. And there was a slight association with breed group, showing terriers and hounds as the most likely to eat feces, and poodles the least.
More significantly, better than 80% of coprophagic dogs preferred their feces fresh. Less than two days old, in most cases.
Older than that, and most of the dogs weren’t interested. And this freshness finding supports the researchers’ main hypotheses: that coprophagic behavior in dogs is an adaptive evolutionary mechanism that dates back more than 15,000 years.
Wolves did it (and still do).
The researchers point out that wolves usually defecate away from their dens, in part because their feces contain intestinal parasite eggs. But if a wolf was too sick or injured to move and had to defecate at home, those parasitic eggs became a potential problem. But because parasite eggs don’t typically hatch into infectious larvae for a couple of days, the feces wouldn’t necessarily be dangerous right away.
So, what to do with the poo?
The researchers theorize that wolves would eat the feces to get rid of it and protect the pack. And while that might sound extreme, remember that it’s not like those wolves had a pooper scooper handy. Or the opposable thumbs necessary to use one if they did. And if they ate it fresh, right away, before the larvae eggs hatched, it would be safe to eat.