Every dog owner has had the same thought in the pet food aisle. You're considering the 25-pound bag of Healthy Vita-Premium Radiance Meal, which has 326 vitamins, grains that never suffered the pesticide's breath, and promises to make the beast's coat as shiny as a freshly waxed car. Or you could get the Jumbo Sack of Beast Nodules, which is probably the same thing. You know your dog doesn't really care if his wet food is a Tuscan Medley. Your dog wants horse guts and maybe some bacon rubbed in squirrel musk

You pick up the huge sack, and you buy some waste disposal bags, and consider that your pet is a machine for converting all the stuff in the big bag to stuff that goes in the small bags. it would be more efficient to eliminate the middleman, but it's the middleman who's doing the eliminating.

Which brings us to the Minnetonka dog-waste problem. As the Star Tribune's Kelly Smith reported this week, the city is struggling to deal with stegosaurus-sized mounds of uncollected waste. My wife has noted the same thing at Minneapolis's Franklin-Terrace off-leash dog park, and it's all right by the entrance. As if people look at it and say to themselves "now remember which pile was ours so we can get it on the way out."

But perhaps the critics should be sympathetic. Obviously, they're not dog owners. Obviously, they have no experience with walking a dog. It's like this: you're trotting along, preferably taking up the entire path so joggers have to go around or leap over the leash like it's Hopscotch Day on the trails. The dog stops, as dogs will do when they smell something whose esoteric foulness escapes your rude untutored nostrils.

When you look you discover that the dog has assumed a peculiar squatting posture, and — this is when it gets really weird — seems to be producing something that reminds you of the Play-Doh Fun Factory you had as a kid, except that extruded things in the shape of stars. What is going on here? What is the dog doing?

The dog is … is doing that? Again? You remember seeing the dog do that a few years ago, but figured it was a one-off. Or a number two-off, if you will. But now it's happening again.

What can you possibly do? No, you didn't bring a bag. You didn't bring a metal umbrella in case of a meteor shower, either. Well, best just walk away. It's natural, after all. It'll return to the earth and fertilize the park, naturally. Now that you think of it, you're doing the park a favor.

Later the dog finds some other creature's leavings, and you're relieved, because obviously another dog was, well, relieved, so you're not the only one.

That's one explanation, and requires a high level of self-delusion in the dog walker. The other explanations:

• The dog walker does not subscribe to the newspaper. Every copy of the Star Tribune comes in a complimentary dog-waste sheath you wear like a sleeve; it extends past your elbow. This is a competitive advantage the online news services cannot offer, and don't think they haven't tried; Huffington Post is probably considering giving away small scoops that snap into the headphone jack on your phone. But the newspaper bags are cheap, and knot easily; if you're lucky you will soon come across a public garbage bin, and you can whip that thing around like David's sling and smote the can from a distance without having to touch anything.

• The dog walker was left without a bag. By accident. This happens. You realize you have no bag, and then comes a performance of theatrical dismay that rivals Macbeth's lamentations. You pat your pockets, you look around as if the Offal Fairies had made a bag materialize under a bush, and then you say something slightly stern to the dog, along the lines of "of all the times you had to go."

The dog looks at you without a jot of comprehension, because this thing you got about picking it up is totally counterproductive. That's part of his whole scent-promotion scheme, but you get all weird about it. It's like someone coming into your office and erasing your web-browser bookmarks. Dude, why?

• Or, people are jerks. They don't understand the Tragedy of the Commons. You know: the cautionary tale that says when no one is responsible for the area where all the cattle graze, and it gets overgrazed. Same thing, except imagine a vast sea of …

No don't. Sorry. But you know what I mean.

There's no excuse for not picking up after your dog. I take my dog to the dog park by the airport, and the minute the leash is unclipped he bolts off at 47 miles per hour because he picked up the scent of an old pal irrigating a tree 400 yards south. Even then you can tell if your mutt has assumed the position, as the police say.

If people do not pick up after their dogs, and parks struggle with the accumulation of odoriferous goop, something will happen.

Dogs will be banned.

Extreme fines will be imposed. If the park let it be known that small drones with cameras were flying overhead and the fee for not scooping the ordure was $1,500, people would use leaves and put it in their jacket.

Dogs will be required to wear diapers. For dogs, this is cruel, like putting a gag over the mouth of a radio announcer.

So pick up after your dogs. This concludes this week's recitation of obvious things that have escaped the attention of people who ruin it for everyone else. Next week: people who park so poorly they take two spots, and is there something you could leave on their hood to let them know they did it wrong?

jlileks@startribune.com • 612-673-7858