One of the most persistent questions I’ve received over my career is this: Why do dogs eat grass?

The answer is simple: Nobody knows.

There’s a correlation between gastrointestinal upset and grass eating. This has led some people to posit that dogs eat grass in order to make themselves vomit. I think the notion of grass as a vomit inducer is absurd for two reasons:

First, plenty of dogs eat grass when their stomachs feel fine, and they don’t vomit afterwards. Second, who in his right mind would believe that a hedonistic creature such as a dog – a creature that happily copulates in public, steals food off of tables, eats garbage, sniffs butts, and licks its own genitals – would ever WANT to throw up?

Dogs don’t suffer from self-image problems and bulimia. They may eat grass when they feel sick, but I don’t believe they do it in order to make themselves more sick. Let’s go back to that first reason. Plenty of dogs eat grass whether they feel sick or not. Some dogs just seem to like grass. My pal Buster is one of them. He is especially fond of the tender young grass shoots that sprout in the spring. This brings us to another of the most common questions I have received over my career: Is it safe for dogs to eat grass? My answer to that question is no.

Lawns may be treated with toxic chemicals. Grass is home to parasites such as roundworms. Grass may become stuck in the mouth and the pharynx (the structure at the back of the throat). And, as I discovered recently, grass may be the source of another significant physical menace.

My day started off well enough. Buster and I were in Tahoe, and although spring was in full force back home in San Francisco, Tahoe was still markedly wintery. We slept in and then enjoyed breakfast (mine was leisurely; Buster is a Labrador retriever mix, so his was consumed in 30 seconds). We then set out on our morning constitutional. Buster lifted his leg on several snow banks. We made it to the end of the road, and we started on a National Forest path. Buster likes to poop in the woods, and we hadn’t made it 20 feet beyond the road before he started to dilate. He darted off the path to move his bowels. That’s when things went wrong. Buster pooped without incident (he always does), but then he became distressed. He walked back to the trail, but continued to posture and strain. I began to worry. Had he prolapsed his rectum? I corralled him, lifted his tail, and promptly identified the source of his distress. It was the mother of all dingleberries.

The day before I had observed Buster chowing down fresh green grass sprouts in our yard. A number of these stalks were now sprouting from Buster’s anus, replete with turd fragments that dangled several inches below the source. The fragments bounced on the backs of Buster’s thighs as Buster danced and strained in an effort to rid his rectum of the mess. This called for quick action.

I tossed aside the ski pole that I carried to help with balance in the snow. I shed my gloves. I begged Buster to be still, but he refused. The only thing that seemed to bother him more than the dingleberry was my attempt to deal with the situation. Buster twisted and pranced. He had a knack for catching his leash under his tail, where it rubbed on the dingleberry. I peeled a poop bag off of the leash and, with great difficulty (considering the agitated dog at the end of the line) opened it — whereupon I discovered that it had a massive hole at the grabbing end. I maneuvered my hand to the intact middle of the bag and after a bit of chasing managed to reach my pal’s anus.

I wish I could say that one gentle tug was all it took. Sadly, each of the half dozen grass stalks required individual extraction. When the miserable operation was complete I attempted to wrap the defective poop bag in another bag, only to discover that the new poop bag also had a massive hole. I did my best to wrap things up, but it was not a pleasant endeavor.

Buster, much relieved, and I, very dejected, headed back to the cabin. The scars from this incident (my scars — Buster seems to be fully recovered) may take a while to heal. I officially recommend, for your sake as well as your dog’s, that you not allow him to eat grass.

(Shutterstock images: Bowl with grass, dog pooping)