Some dogs poop while walking. A superpower?
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Heiwei Miaomiao asked: some dogs can poop while they walk. Do they have a superpower? When you go, you stop, and squat or sit down. But some dogs just hunch their backs and keep walking. One step, one piece. How do they do it? The secret isn't in the legs. It's in the long tube inside the belly.
Food passes through the stomach and small intestine. What's left moves into the large intestine, slowly packing into poop. The large intestine isn't a lifeless pipe. It tightens itself, ring after ring, pushing the poop toward the exit. It's like squeezing toothpaste: push from the bottom of the tube, and it comes out the top.
Except toothpaste needs a hand pressing from outside. The gut does it with its own rings of muscle. Since the tube squeezes itself, the legs don't need to help. Walking or standing still, the poop keeps moving out. So why does it so often happen mid-walk? Scientists actually measured it.
In 1991: scientists fitted six dogs with tiny sensors along the large intestine. Then had them run on a treadmill for an hour. Soon after the dogs started running, the gut made one giant squeeze. From start to end. Right after that, the dogs pooped. Empty stomach or full, it was the same. Only six dogs, but the direction is clear: moving gets the gut squeezing harder.
That's why so many dogs need to go just a few steps into a walk. What about us? When we stand, the last stretch of gut before the exit is pulled forward by a sling of muscle, bent to about ninety degrees. Like a toothpaste tube pinched at the neck, nothing comes out. That bend keeps us from leaking while we walk.
When it's time to go, we squat, the muscle relaxes, and the bend straightens a lot. So we have to stop and get into position. Dogs may walk while pooping for other reasons too. They have two little pouches by the bottom that hold their scent. Passing poop squeezes them. Some people guess that walking spreads the scent wider. That's just a guess, nobody has proved it.
Other dogs are just too excited to stand still. Or they're older, and their legs and back hurt too much to squat for long. So if your dog has always done this and the poop looks normal, don't worry. But if it suddenly starts, or can't hold it, or the poop turns runny or bloody, take it to the vet and follow their advice. So it's not a superpower. The gut squeezes its own toothpaste, and walking helps it squeeze harder.
Heiwei Miaomiao, does your dog stop to poop, or poop on the go?
One step, one drop
黑尾喵喵 asked in the comments: some dogs can poop while walking. Do they have a superpower?
When you go, you have to stop and squat or sit. But some dogs just arch their back and keep walking.
No superpower. The secret isn't in the legs. It's in a tube in the belly that squeezes itself.
A toothpaste tube that squeezes itself
Food passes through the stomach and small intestine. What's left goes into the large intestine and becomes poop.
The large intestine isn't a still pipe. It tightens ring by ring, pushing poop toward the exit. Like squeezing toothpaste from the bottom of the tube until it comes out the top.
Where the comparison breaks: a hand squeezes toothpaste from outside, but the gut squeezes with its own rings of muscle.
The tube squeezes on its own, no legs needed. Walking or standing, the poop keeps moving.
Six dogs on a treadmill
In 1991, researchers in the US put small sensors on the large intestines of six dogs to measure squeezing, then had them run on a treadmill for an hour.
Soon after the dogs started running, the gut made one giant squeeze, pushing from start to end. Right after that, the dogs pooped. Empty stomach or full, same result.
Moving makes the gut squeeze harder. That's why many dogs poop a few steps into a walk.
It was only six dogs, over thirty years ago, but the direction is clear.
The 90° bend in humans
When we stand, a loop of muscle pulls the last stretch of gut forward into a bend of about 90°. Like a pinched toothpaste nozzle: nothing comes out.
The bend helps us hold it, so nothing leaks while we walk. When we squat to go, the muscle relaxes and the bend straightens a lot.
So we have to stop and get into position.
Two little pouches by the bottom
Dogs have two little pouches beside the bottom, filled with their own scent. Poop squeezes them on the way out, leaving a mark (dogs also use scent when picking a potty spot).
Some guess that pooping on the move spreads the scent wider, like dogs lifting a leg with nothing left. That's only a guess; nobody has proven it.
Other dogs are just too excited to stand still. Or they're older, with sore legs and backs, and can't squat for long.
When to see the vet
黑尾喵喵, does your dog stop to poop, or poop on the go?
Quick check
What mainly lets a dog poop while walking?
The gut is like a toothpaste tube that squeezes itself, no legs needed; walking just makes it squeeze harder.
