Difficulty Defecating in Dogs: Causes of Straining to Poop, Symptoms and When It’s an Emergency

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.

Don’t jump to conclusions if your dog straining to poop is the only clue

Your dog could be constipated, sure, but it might just as easily be the tail end of a diarrhea episode or something sneakier like an obstruction.

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 proof, you have no proof at all. Without those firm indicators, look closer at other symptoms like vomiting, bloating, or lethargy to get the full picture.

Constipation versus diarrhea

Diarrhea is a more common cause of straining to defecate than constipation.

But diarrhea means lots of runny poop coming out all over the place, doesn’t it? Yes and no—it’s not always a total flood.

When JD would eat something naughty, he’d get visible diarrhea for one or two eliminations, but then he’d keep going and strain 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 significant intestinal diarrhea can look like constipation. The key symptom difference? With diarrhea-related straining, you might notice initial loose stools, mucus, or urgency before the unproductive efforts kick in. Track the whole sequence to spot patterns.

Constipation ramification

Constipation can become a serious problem if left unchecked—it’s not just a one-off “oops, too many bones” situation.

The longer the poop stays in your dog’s colon, the harder it becomes and the tougher 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 won’t be able to contract well enough to move the poop out.

With severe constipation or obstipation, your dog might end up needing to be hospitalized, and damage to the colon’s ability to push out poop can turn defecation issues into a recurring or permanent problem.

Spotting these escalating symptoms—such as persistent straining, distended belly, vomiting, or loss of appetite—can help you recognize when the situation shifts from wait-and-see to “get-help-now.”

Causes of constipation in dogs

Constipation may or may not have anything to do with your dog’s diet—sometimes it’s environmental, behavioral, or a sign of something deeper brewing.

Potential causes of constipation in dogs include:

• inedible items e.g., dirt, grass, hair, bits of toys or fabric—these can clump up and block the flow, turning poops into sporadic pebbles
• fiber-deficient diet, which leaves stools too compact without enough bulk to move smoothly through the system
• dehydration, often from hot days, illness, or just not drinking enough, making everything drier and harder to pass
• anal sack disease, where impacted or infected glands make the whole area sore and the dog is reluctant to go
• prostate issues in males, enlarging and pressing on the colon, leading to strained efforts
• matted hair around the rear, especially in long-haired breeds, creating a physical barrier that’s uncomfortable
• insufficient activity, slowing down gut motility and letting things stagnate
• orthopedic issues that make eliminating painful, like arthritis or back problems causing awkward postures
• tumors or growths that obstruct or disrupt normal bowel function.

Diet can affect how hard the stools are. When Cookie overate bones, parts of her stool became hard. Insufficient fiber or water intake can also cause hard stools. Because Cookie loved her bones, I offset that by increasing her fiber intake. She did get enough water from both her food and her drinking. It was only now and then that the constellation of things ended 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 the “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 incredible 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 pet health insurance for him. JD and Bruin routinely threw 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 drugs, and neurological problems can also 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 have, such as with Cookie, where I know the reason for her occasional hard poops, added some fiber to her food, I would never even consider randomly experimenting with human laxatives, enemas, or mineral oil—those can backfire in ways you don’t expect, like causing more irritation or imbalances.

Especially if I didn’t know for sure what was 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.

When is difficulty defecating in dogs an emergency?

Difficulty Defecating in Dogs: breed-specific notes

• Chondrodystrophic breeds (e.g., Dachshunds, Corgis) may strain more due to spinal issues (intervertebral disc disease) affecting posture and causing pain during elimination
• Brachycephalic breeds (e.g., Bulldogs, Pugs) could face higher anal gland problems from anatomy-related scooting/straining
• Large breeds (e.g., German Shepherds) might be prone to GI or orthopedic issues (hip dysplasia) that slow motility and lead to constipation

Related articles:
What’s in the Poop?
Treating Dog Constipation at Home: Can You Help Your Constipated Dog?

Further reading:
Difficult Defecation and Blood in Stool in Dogs