Some dogs will eat feces or “poop” from other dogs or even their own poop, and sadly, almost every dog will eat a cat’s fecal material. This behavior is called coprophagia and it is very hard to train away. So why in the world do they do it? Coprophagia is considered normal behavior (although gross) in canines. All of the reasons why dogs engage in coprophagia are not known, but there are some pretty good theories why dogs eat feline fecal waste.
Believe or not, it all comes down to the eye of the beholder!
Because cats are obligate hyper-carnivores (required meat eaters), they have a decreased ability to digest certain things, especially carbohydrates. The dog might be able to sense or smell these partially digested components and think that the fecal matter is still a food item (although it is isn’t a great source of nutrients). Your cat’s body is not able to use any of these nutrients, but your dog wonders why in the world she would throw them away. In the interest of survival, your dog is following the “waste not, want not” rule.
As always, a balanced diet (for the dog and the cat, if possible-and they can’t eat the same diets) is a good idea just to be sure there is no vitamin deficiency. Because we know that partially digested carbohydrates in feline feces may be an attractant, it might be wise to be sure there aren’t excessive carbohydrates in your cat’s diet to attract your dog to the litter box. If the cat is your own, you can make the box inaccessible to curious canines, but if your dog is uncovering errant cat poop on walks or in the yard, there is not as much you can do.
Some people suggest walking “poop eaters” in a basket muzzle, so you can be sure what goes in their mouths, but if you do, your dog must be trained to accept the basket muzzle first. You can make the muzzle seem like a good idea by smearing it with peanut butter and doing only short sessions while wearing it at first. Most dogs don’t mind and it will put your mind at ease on walks in areas where cat poop is a possibility.
Try to remember that his nose and his instincts are telling him that the poop is not waste at all, and be patient. Of course, keep your dog and cat on a comprehensive dewormimg program, overseen by your veterinarian, to keep everyone safe and healthy.