Dog Constipation Symptoms and When to Call Your Vet

A constipated dog strains, squats again and again, and passes little or nothing, or only small, hard, dry stools. If your dog hasn't had a bowel movement within 48 to 72 hours of the last one, call your vet, and call sooner if your dog seems uncomfortable. If your dog is straining to pee and little or nothing comes out, call now: that can be a blocked bladder, not constipation.

Caught early, constipation is usually easy to treat. The catch is that straining has several causes, and a few of them can't wait.

Signs of constipation in dogs

Vets call straining to poop tenesmus, and together with firm, dry stools it's the classic sign of constipation, according to the Merck Veterinary Manual. Watch for:

• straining, whining or crying out while trying to poop
• many attempts with little or nothing to show for them
• small, hard, dry stools
• circling, squatting often or scooting along the ground
• a little watery stool or mucus and no normal poop: liquid squeezes past the hard mass and is easy to mistake for diarrhea
• a few drops of blood from the straining
• stool or matted hair stuck around the anus
• thin, ribbon-like stool, which can mean something is pressing on the rectum, such as an enlarged prostate or a mass
• a tense, sore belly; your dog may cry or growl if you touch the belly or lower back
• eating less, vomiting or weight loss

How often should a dog poop? Most dogs go one to three times daily (PDSA), so a break in your own dog's pattern is what to notice. VCA Animal Hospitals advises calling your veterinarian if your dog fails to produce a bowel movement within 48 to 72 hours of the previous one. Treat that as the outside limit, not a countdown: straining, pain or vomiting means calling sooner. More in how long a dog can go without pooping, and the dog poop color chart shows what normal and worrying stool look like.

Constipated or something else?

A dog hunched and pushing might be trying to pass a hard stool. It might also be something very different, which is why a straining dog needs a vet's exam rather than a guess at home.

The look-alike owners miss most is a blocked bladder. A dog straining to pee looks a lot like a dog straining to poop, and the Merck Veterinary Manual notes that owners sometimes mistake a urinary blockage for constipation; in dogs, bladder stones are a common cause. It happens in male and female dogs, though it's more common in males because their urethra is longer and narrower. PetMD puts the stakes plainly: a dog with a complete blockage will die within days if it isn't relieved.

The other look-alikes, briefly:

• Diarrhea or colitis. An inflamed colon makes dogs strain during and after pooping, with frequent soft stools, mucus and sometimes bright red blood (VCA). The dog keeps passing something; a constipated dog passes little. See what colitis in dogs means.
• A swallowed object. Vomiting, a sore belly and no poop together point to an intestinal blockage, which is an emergency.
• Prostate trouble, common in unneutered males. An enlarged prostate can press on the colon and cause straining, blood in the urine and ribbon-like stools (Merck).
• A perineal hernia, a bulge beside the anus seen most often in unneutered males around 6 to 8 years old. The bladder can slip into it and block urine flow (Merck).
• Sore anal sacs, which make pooping hurt, so dogs scoot, lick and strain.

When to call your vet

Call now, day or night, if your dog:

• is straining to pee and little or no urine comes out (male or female)
• is vomiting and not pooping, or may have swallowed a bone, toy or other object
• has a swollen, tense or very painful belly
• is weak, very quiet or collapses

Call today if your dog:

• hasn't pooped within 48 to 72 hours of the last bowel movement
• is straining, crying or passing only small, hard stools
• has blood or mucus with the straining

• is eating less than usual

Don't wait out the full 48 to 72 hours if your dog is older, an unneutered male, on a new medication, or has been constipated before. Call as soon as you notice the change.

Mention it at your next visit if your dog's stools have been firmer than usual for a while, but your dog is still pooping, eating and comfortable. Constipation that keeps coming back deserves a look, because the cause may need treating.

What is constipation, and why does it happen?

The Merck Veterinary Manual defines constipation as "the infrequent or difficult evacuation of feces, which are typically dry and hard." The colon pulls water out of what's left of the food, so the longer stool sits there, the drier and harder it gets, especially in a dehydrated dog.

Two terms you may hear from your vet:

• Obstipation: constipation so severe that the dog can't pass the hard mass at all. It needs a vet to clear it.
• Megacolon: a stretched, weak colon that can no longer push stool out. It's uncommon in dogs and can be a cause or a result of long-term constipation (VCA).

What causes constipation in dogs?

Any dog can become constipated at any age, though senior dogs are affected more often (Sawtooth Animal Center). VCA names eating irritating or indigestible things, such as plant matter or bones, as the most common cause. Most other causes fit the three groups Merck uses.

Something inside the colon that won't pass:

• bones, grass, gravel, toys, fabric or other things a dog shouldn't eat
• hair swallowed during grooming, especially in long-haired dogs or dogs that lick themselves a lot
• not drinking enough, or an illness that dehydrates, such as kidney disease
• holding it in because pooping hurts (sore anal sacs, arthritis) or because of fear or stress
• a mass in the colon or rectum, or matted hair and stool blocking the anus

Something pressing on the colon from outside: a narrowed pelvis after an old fracture, an enlarged prostate in unneutered males, or a perineal hernia.

Nerve, muscle and hormone problems that slow the colon: spinal cord or nerve damage, an underactive thyroid (hypothyroidism), hyperparathyroidism, or megacolon.

Everyday habits count too: VCA and PDSA list a sudden diet change, too little exercise and being very overweight. Some medicines slow the gut, including antihistamines, diuretics, opioid pain relievers and sucralfate. Don't stop a prescribed drug on your own; ask your vet.

What your vet will do

Before the visit, jot down when your dog last passed a normal stool, whether your dog is peeing normally, any vomiting or appetite change, anything your dog may have chewed or swallowed, recent food changes, current medications and any old injuries such as a pelvic fracture.

At the clinic, your vet will feel the belly and usually do a rectal exam, which also checks the prostate and looks for a hernia, a narrowing, a mass or a foreign object. X-rays show how much stool is in the colon and whether something is blocking it. Blood and urine tests follow, with a thyroid test, ultrasound or colonoscopy when constipation keeps coming back.

Treatment depends on the cause: fluids for dehydration, an enema at the clinic (sometimes under sedation), or removing the hard stool under general anesthesia. Any laxative or medication that helps the colon contract is chosen and dosed by your vet once a blockage is ruled out, and a diet change may mean more fiber or less. Surgery is for a swallowed object, a hernia or a tumor, or, rarely, removing part of the colon when severe constipation doesn't respond to medical treatment; most dogs do well after it.

Afterward, your vet may suggest probiotics or a therapeutic diet. Stick to the plan: piling on extra fixes can swap constipation for diarrhea.

Why enemas, laxatives and milk stay off the home menu

• Human enemas can poison dogs. Phosphate enemas sold for people throw blood salts dangerously out of balance. The ASPCA Animal Poison Control Center notes this poisoning is more likely in cats and small dogs, although marked signs have been reported in large-breed dogs, and signs generally start within 30 to 60 minutes. Some dogs in its records died (dvm360). The Kennel Club says never give an enema yourself.
• Laxatives can backfire. Merck warns they can worsen dehydration, and stimulant types must not be used if the bowel is blocked, which only your vet can rule out.
• Oils aren't a shortcut. A dog can inhale mineral oil given by mouth and get pneumonia, Merck warns.
• Skip the milk. Many dogs are lactose intolerant.

How to help your dog safely

These steps support your vet's plan and help prevent the next episode. They don't replace a vet visit for a dog that's straining or hasn't pooped in 48 to 72 hours.

1. Keep fresh water out all the time. Water keeps stool soft. Ask your vet whether wet food would help.
2. Keep your dog moving. Walks and play help the gut, and plenty of trips outside mean your dog doesn't have to hold it in.
3. Feed on a regular routine, and change foods gradually rather than overnight.
4. Ask your vet before adding fiber, pumpkin or a supplement. Some constipated dogs need more fiber and some need less, and Merck advises hydrating a dog before adding fiber, or the fiber itself can pack into the colon.
5. Don't feed bones, and keep toys, socks, rocks and trash out of reach.
6. Keep the back end tidy. If hair around the anus is matted with stool, have a groomer or your vet clip it rather than cutting near the skin yourself.
7. Work toward a healthy weight with your vet.

Outlook

Most dogs recover quickly once the hard stool is cleared and the cause is treated, VCA notes; some with an underlying disease need a special diet or medication for life. Constipation that drags on or keeps coming back is harder on the colon, which is the best reason to call early.

Quick answers

Is it an emergency if my dog hasn't pooped in 2 days? On its own, in a dog that's bright and eating, it's a reason to call your vet today. If your dog is also vomiting, has a painful belly, may have swallowed something, or is straining to pee, call now.

Can constipation make a dog vomit? Yes, badly constipated dogs can stop eating and vomit. But vomiting with no poop is also a classic sign of an intestinal blockage, so call now.

Originally written by Akosua Kumi Nyarko. Updated by the I Love Veterinary editorial team.

Sources

• Merck Veterinary Manual: Constipation, Obstipation, and Megacolon in Small Animals
• Merck Veterinary Manual: Obstructive Uropathy in Dogs and Cats
• Merck Veterinary Manual: Prostatic Diseases in Small Animals
• Merck Veterinary Manual: Disorders of the Rectum and Anus in Dogs
• VCA Animal Hospitals: Constipation in Dogs
• VCA Animal Hospitals: Colitis in Dogs
• PetMD: Urinary Tract Blockage in Dogs
• dvm360 (ASPCA Animal Poison Control Center): Hypertonic phosphate enema intoxication in dogs and cats
• The Kennel Club: Constipation in dogs
• PDSA: Dog constipation
• Sawtooth Animal Center: Constipation in Dogs

This article is for general information and is not a substitute for advice from your veterinarian.