Difficulty Defecating in Dogs: Why Is My Dog Straining to Poop?
If your dog is straining to defecate, it’s merely constipation, isn’t it? Not so fast.
Constipation does make evacuating stool difficult, but it is far from the only reason that can make your dog strain to defecate.

If your dog straining to poop is the only inkling, don’t jump to conclusions.
Do you have any hard evidence? Yeah, I stooped to a cheesy pun. But I mean it. Do you? Unless you have unusually hard poops as a proof, you have no proof at all.
Diarrhea is more common than constipation.
But diarrhea means lots of runny poop coming out all over the place, doesn’t it? Yes and no.
When JD would eat something naughty, he’d get visible diarrhea for one or two goes but then he’d just keep going and straining with very little or nothing coming out. Was he constipated? No. But his bowel was so irritated that he felt like he had to keep trying to get relief.
That’s why the straining associated with large intestinal diarrhea can look like the straining associated with constipation.
Constipation can become a serious problem.
The longer the poop stays in your dog’s colon, the harder it becomes and the harder it will be to pass. If enough poop backs up, it can stretch your dog’s intestine to the point it will become unable to do its job — a condition called obstipation. The colon normally contracts to move the poop toward the exit. But at some point, the colon simply won’t be able to contract well enough to move the poop out. With severe constipation or obstipation, your dog will probably end up having to be hospitalized, and the loss of colonic function can make problems defecating a recurring or permanent problem.
Constipation may or may not have anything to do with your dog’s diet.
Diet can affect how hard the stools are; when Cookie manages to eat too much bone, parts of her stool do get hard. Insufficient fiber or water intake can also cause hard stools. Because Cookie loves her bones, I offset that by increasing her fiber intake. She does get enough water both from her food and drinking. It’s only every now and then when the constellation of things end up with the odd hard poop.
Jasmine would get constipated during periods of restricted exercise; after surgeries or during recovery from injury. Lack of exercise can also be a factor leading to constipation. In Jasmine’s case, on top of everything, her intestines were on a “lazy side” due to her IBD. It was up to us to do our best to keep things moving.
Other factors, even stress, can end up messing with healthy elimination.
Watch out for gastrointestinal blockages/obstructions.
Given the range of weird things they managed to have eaten, it is amazing that neither of our dogs ever ended up with intestinal obstruction. That includes accidentally swallowed sock, sticks, rocks, pieces of toys and other things that seemed edible at the time. JD’s inclination to stuff himself with horse poop, grass, and sticks was why I got a pet health insurance for him. Both JD and Bruin would routinely throw up lumps of such debris the morning after a day at a horse farm.
An obstruction can be partial or complete, and symptoms depend on where in the GI tract the obstruction is. Symptoms can include an inability to produce poop, diarrhea, vomiting, abdominal pain, weight loss, dehydration, and shock.
Don’t fool yourself; such a problem might require surgery and can be life-threatening.
Not every obstruction might be your dog’s fault.
There are medical conditions that can cause the blockage such as enlarged prostate in male dogs, rectal hernias, and, unfortunately, even cancer.
Infected anal glands, injuries, the use of certain types of drugs, and neurological problems all too can result in difficulty defecating.
Your dog straining to poop might be an emergency or a serious medical issue.
How quickly your dog needs to see a vet depends on how badly they look. Is there pain? Vomiting? Lethargy? Then they need medical help quickly.
While I might, such as with Cookie where I know what the reason for her occasional hard poops is, add some fiber to her food, I would never even consider randomly experimenting with human laxatives, enemas or mineral oil. Especially if I didn’t know for sure what is going on. Being sure is a tricky business. One of hubby’s favorite lines is, “I know you’re sure but are you right?” He doesn’t say that to me, of course, I’m never sure unless I’m right.
Related articles:
What’s in the Poop?
Further reading:
Difficult Defecation and Blood in Stool in Dogs