Wondering what’s at root of dog’s grass-eating habit

Dear Cathy: Every two or three weeks, Anubis goes outside, walks around the yard very selectively eating grass, throws up a mixture of grass and yellow slimy liquid, and happily comes back in.

My vet is at a loss, and there is nothing I can relate the vomiting to.

Anubis is a northern spitz type, about 60 pounds and 10 years old, with no health issues except for a sebaceous adenoma on the back of his neck.

Any ideas will be appreciated. — Keri, Catasauqua, Pennsylvania

Dear Keri: No one knows for sure why dogs eat grass and then throw up the slimy liquid you describe. Even though it’s a fairly common behavior that most dogs do at one time or another, it naturally stresses most pet owners, who worry their dog is ill.

While your dog could be ill, if Anubis has been to the vet and has a clean bill of health, then chances are the behavior is being triggered by something else. Some people think a dog that does this might have a nutritional deficiency. If your dog’s food meets all nutritional requirements, this would not be the case. (Look for the AAFCO, or Association of American Feed Control Officials, label.)

Some say dogs eat grass because they are bored. Dogs, like people, can’t do two things at once, so if you play with or otherwise distract your dog from eating grass while outside, then eventually the behavior may stop.

Some think dogs may have tummy troubles and are trying to self-soothe. It’s not been proven, but it’s certainly possible.

Others say dogs may need additional fiber in their diet. In a published study, a miniature poodle who ate grass and vomited every day for several years stopped the behavior entirely after his owner introduced fiber into his diet. So maybe add a teaspoon or two of pumpkin to his food to see if that helps.

If nothing helps, rest assured Anubis’ behavior is fairly normal among dogs and not one to be overly concerned about if your vet is not worried and it happens infrequently. The only danger to your dog would be if the grass had been recently treated with a pesticide.