The most common reason dogs get constipated is eating something irritating or indigestible, like bones, sticks, grass, or other plant matter. Most healthy adult dogs poop once or twice a day, typically about 30 minutes after eating or right after waking up. If your dog hasn’t had a bowel movement in two or more days, or is straining without producing much, something is off.
Common Causes of Dog Constipation
Beyond swallowing things they shouldn’t, dogs that groom themselves excessively or have long hair can develop constipation from ingested fur blocking things up. A sudden change in diet, new treats, or raiding the trash can also throw off digestion. Treats should make up no more than 10% of your dog’s daily food intake, and overdoing it is a surprisingly common trigger.
Dehydration is another frequent culprit. Dogs need roughly 1 ounce of water per pound of body weight each day. A 50-pound dog, for example, should be drinking about 50 ounces (just over 6 cups). If your dog isn’t getting enough water, especially during hot weather or after exercise, the colon absorbs more moisture from stool than it should, leaving it hard and difficult to pass.
Lack of exercise plays a role too. Physical movement helps stimulate the normal contractions of the intestines that push stool along. Dogs that are sedentary, recovering from surgery, or dealing with joint pain from arthritis may develop sluggish bowels simply because they aren’t moving enough. Pain itself can contribute: a dog with sore hips or knees may avoid squatting to defecate, which leads to stool backing up.
Several medications cause constipation as a side effect, including antihistamines, diuretics, and narcotic pain relievers. If your dog recently started a new medication and then stopped pooping normally, that connection is worth raising with your vet.
Less Obvious Medical Causes
Hormonal imbalances can slow the gut. Hypothyroidism, where the thyroid gland underproduces hormones that regulate metabolism, is one of the more common ones in dogs. Overactive parathyroid glands can also disrupt normal bowel function by affecting calcium levels in the body.
In intact (unneutered) male dogs, an enlarged prostate can physically press against the colon and narrow the passage. When this happens, stools often come out thin or ribbon-shaped rather than being absent altogether. Tumors or masses in the colon or rectum can create a similar obstruction.
Neurological diseases that affect the nerves controlling the colon, old pelvic fractures that healed in a way that narrows the pelvic canal, and behavioral issues like fear or anxiety can all contribute. Some dogs refuse to defecate in unfamiliar environments, during thunderstorms, or after a stressful change like a move or a new pet in the household.
What Constipation Looks Like
The obvious sign is straining to defecate with little or nothing to show for it. The stool that does come out is usually hard, dry, and sometimes foul-smelling. Your dog may circle, squat repeatedly, or cry while trying to go. Some dogs lose their appetite, seem lethargic, or vomit when constipation becomes more severe.
It’s easy to confuse straining from constipation with straining from diarrhea or a urinary problem. Watch what actually comes out. If your dog is producing small amounts of liquid stool while straining, that could be diarrhea squeezing past a blockage, not true relief.
When It Could Be Something More Serious
Simple constipation and a gastrointestinal obstruction can look similar at first, but an obstruction is an emergency. The key differences: obstruction tends to cause more frequent and more severe vomiting, especially if the blockage is high up in the intestinal tract. Dogs with obstructions may also develop abdominal swelling, fever, dehydration, or signs of shock. If your dog is vomiting repeatedly, refusing all food, and seems to be in significant pain, that warrants an urgent vet visit rather than a wait-and-see approach.
What You Can Try at Home
For mild, short-term constipation in an otherwise healthy dog, a few simple interventions often work.
Plain canned pumpkin (not pumpkin pie filling, which contains sugar and spices) is one of the most commonly recommended home remedies. The fiber and moisture content help soften stool and get things moving. The American Kennel Club suggests adding 1 to 4 tablespoons per meal, starting at the lower end to avoid adding too much fiber at once. For a small dog, one tablespoon is a reasonable starting point. For a large dog, you can work up to four.
Make sure fresh water is always available and encourage your dog to drink more. Adding a splash of low-sodium broth to the water bowl works for some dogs. Increasing exercise, even just adding a longer walk, can help stimulate the bowel. If your dog has been eating a lot of bones or hard chews, stop offering them until things normalize.
Veterinary Treatment Options
If home remedies don’t produce results within a day or two, or if your dog seems uncomfortable, a vet visit is the next step. The vet will typically feel your dog’s abdomen to check for a firm, stool-packed colon and may take X-rays to rule out obstructions or structural problems.
For straightforward constipation, treatment usually involves stool softeners or laxatives. Osmotic laxatives work by pulling water from the body into the intestinal tract, creating softer, wetter stool. These are generally well tolerated, though finding the right dose sometimes takes a bit of trial and error. In some cases, a medication that strengthens the contractions of the large intestine may be prescribed to help move things along.
Dietary changes are part of the longer-term plan, though the direction depends on the cause. Some dogs need more fiber, while others actually need less. Your vet will recommend the right approach based on what’s driving the problem.
Chronic Constipation and Megacolon
Dogs that experience repeated bouts of constipation can develop a condition called megacolon, where the large intestine becomes stretched out and loses its ability to contract normally. The colon essentially becomes a floppy, oversized tube that can no longer push stool through effectively. This is more common in cats, but it does occur in dogs, particularly those with a history of pelvic injuries. Once the colon’s muscular wall degenerates to this point, the damage is often permanent, and management requires ongoing medication or, in severe cases, surgery to remove the affected portion of the colon.
This is why recurring constipation shouldn’t be brushed off as a minor nuisance. Addressing it early, whether through diet, hydration, exercise, or treating an underlying condition like hypothyroidism, prevents the kind of chronic stretching that leads to permanent colon damage.