Hernia in Dogs: Types, Symptoms, and When It's Dangerous

Name: Hernia in Dogs: Types, Symptoms, and When It's Dangerous
Creator: Dr. Zubair Khalid

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-10-03

Hernias in dogs happen when an organ or fatty tissue pushes through a weak spot in the muscle wall that normally holds it in place. Some hernias are soft, painless lumps you can gently push back in, while others trap the intestine and become a surgical emergency within hours. Knowing the hernia in dogs symptoms that signal trouble helps you decide whether to call your vet today or rush to an emergency clinic tonight.

This article is educational and is not a substitute for veterinary diagnosis or treatment.

Quick Answer

A soft, reducible lump (one you can push back in) is often not urgent, but it still needs a vet visit to plan repair.
A firm, painful, or discolored lump is an emergency, especially if your dog is vomiting, drooling, or breathing hard.
Sudden breathing difficulty after a car accident or a fall points to a diaphragmatic hernia and needs emergency care right away [1].
Umbilical hernias are common in puppies and in breeds like Weimaraners, Pekingese, Basenjis, and Airedale Terriers [2].
Most hernias are fixed with surgery, and the outlook is good when the repair happens before tissue becomes trapped.

What Is a Hernia in Dogs?

A true hernia has three parts: a ring (the opening), a sac, and contents (the tissue that slipped through) [2]. The contents can be fat, omentum, or loops of intestine [2]. When the opening is in the belly wall, you may feel a squishy bump under the skin. When the opening is inside the chest, you will not see a lump at all. You will see breathing changes instead.

Hernias can be direct (through a tear in the body wall) or indirect (through a natural opening like the umbilical or inguinal ring) [2]. Hernias present at birth tend to be indirect [2].

The main types

Umbilical hernia. This is the classic "belly button" hernia. It shows up as a soft swelling on the midline of the belly in a puppy. It may contain only fat, or it may contain intestine in more serious cases [2].

Inguinal hernia. This one appears in the groin area, near the inner thigh. It is more common in females but can occur in males, sometimes extending into the scrotum [2]. An inguinal hernia can contain intestinal loops, and a large one may sit next to other abdominal problems [3].

Perineal hernia. This occurs near the anus, which is why owners often search for "hernia in dogs anus." It mostly affects older male dogs and can push the rectum out of position, making it hard to poop.

Diaphragmatic hernia. The diaphragm is the muscle sheet that separates the chest from the abdomen. A break in it lets abdominal organs move into the chest [1]. This can be caused by trauma, such as being hit by a car, or by a defect present at birth [1][4].

Hiatal hernia. This is a sliding hernia at the opening where the esophagus passes through the diaphragm. It often causes reflux, vomiting, and breathing noise, and it is frequently seen alongside flat-faced airway problems [5].

Hernia in Dogs Symptoms: What You Will Notice

The signs depend on where the hernia is and whether tissue is trapped. A hernia in dogs belly area usually shows up as a visible or palpable lump. A hernia in dogs stomach or chest area shows up as breathing or digestive trouble instead.

Signs of a belly or groin hernia

A soft swelling on the midline of the belly or in the groin
A lump that changes size when your dog barks, coughs, or strains
A lump you can gently push back in (reducible)
A lump that feels firm, hot, or painful (not reducible)

Signs of a perineal hernia

A swelling beside the anus
Straining to poop
Ribbon-like or narrow stools
Constipation that keeps coming back

Signs of a diaphragmatic or hiatal hernia

Fast or labored breathing [1]
Trouble breathing that ranges from barely noticeable to fatal, depending on severity [1]
Vomiting, which was the most common sign in one group of dogs with this type of hernia [6]
A bloated stomach if the stomach is trapped, with rapid worsening [1]
Weight loss in long-term, milder cases [1]
Digestive sounds heard in the chest instead of normal lung sounds during an exam [1]

Some dogs born with a diaphragmatic hernia show no signs at all, or only vague problems with breathing or digestion [1]. Others are diagnosed by accident during imaging for something else [6].

If your dog is vomiting and you are not sure why, our guide to Dog UTI Symptoms: How to Recognize and What to Do covers another common cause of that sign, and What Are The Signs And Symptoms Of A Dog With Worms covers a third.

Causes and Risk Factors

Trauma

Being hit by a car is a common cause of diaphragmatic hernia in dogs [1][4]. A delayed hernia can also happen. In one reported case, a dog developed a persistent cough and was found to have a diaphragmatic hernia six months after a car accident, even though earlier imaging and surgery had shown no major damage [7]. Rib fractures that healed can be a clue on imaging [8].

Genetics and breed

Umbilical hernias are seen more often in Weimaraners, Pekingese, Basenjis, and Airedale Terriers [2]. Many dogs with umbilical hernias also have a retained testicle, and a hereditary cause is suspected but not proven [2]. In one review of dogs with a pleuroperitoneal diaphragmatic hernia, Cavalier King Charles Spaniels made up 30 percent of the cases [6].

Age, sex, and other factors

Perineal hernia is largely a disease of older male dogs. Dogs neutered before their perineal hernia repair were 4.4 times as likely to have the hernia come back compared with dogs neutered at the time of repair [9]. Dogs that became fecal incontinent after surgery were 3.4 times as likely to have a recurrence [9].

A sudden rise in pressure inside the belly can also cause a hernia. This is more common in horses during foaling, but the same principle applies to any strong straining [4].

How Hernias Are Diagnosed

Your vet starts with their hands and eyes. They will watch the hernia sac, feel it, and check whether it can be reduced [2]. They will also listen to the chest for lung sounds and for bowel sounds in the wrong place [1].

Imaging does the rest:

Ultrasound helps show what is inside the sac and whether the tissue has blood flow [2].
X-rays (radiographs) are highly diagnostic for diaphragmatic hernia [4]. They can show abdominal organs sitting in the chest [7].
Contrast radiography can confirm the diagnosis when plain films are unclear. In one case, a barium study showed tubular shadows in the chest that turned out to be small intestine and cecum [7].
Minimally invasive techniques are now used in some cases. One report described using a laparoscope through an inguinal hernia to look inside the abdomen and remove part of a mass at the same time [3].

Blood work is often done before anesthesia and to check organ function. In the delayed hernia case, liver values were monitored after surgery to watch for endotoxemia [7].

Treatment Options

Surgery

Surgical closure of the body wall defect is recommended in most cases to lower the risk of intestine becoming trapped later [2]. For diaphragmatic hernia, treatment centers on stabilizing your dog first, then repairing the diaphragm [4]. Surgery is required for a definitive fix [4].

Repair usually means general anesthesia, manual ventilation, and closing the tear through the belly [7]. For hiatal hernia, surgeons commonly perform an esophagopexy and phrenoplasty, and some dogs also get a gastropexy to hold the stomach in place [5].

When surgery is not immediate

If your dog is stable and the hernia is not trapped, your vet may schedule repair instead of operate the same night. If your dog is in respiratory distress, the team will stabilize breathing and circulation first [4]. A dog with a bloated, trapped stomach can get worse very fast and needs surgery without delay [1].

Medical management

Some hiatal hernias are managed with diet and medication before or instead of surgery. Your vet will tailor this to your dog. Never give human acid reducers or any other medication without asking your vet first, because the dose depends on your dog's weight and health.

Table: Hernia Types at a Glance

Type	Where you see it	Common signs	Urgency
Umbilical	Midline belly, puppy	Soft lump, may shrink when pressed	Routine unless firm or painful
Inguinal	Groin or scrotum	Swelling that may contain intestine	Prompt, urgent if painful
Perineal	Beside the anus	Straining to poop, ribbon stools	Prompt
Diaphragmatic	Inside the chest	Fast or labored breathing, vomiting	Emergency if sudden
Hiatal	Esophagus opening	Reflux, vomiting, noisy breathing	Prompt to urgent

Recovery, Outlook, and Long-Term Management

Most dogs do well after hernia repair. In the delayed diaphragmatic hernia case, the dog moved, ate, and urinated normally within 10 days of surgery, and follow-up X-rays showed clear chest and abdominal outlines [7].

Recovery at home usually means:

Restricted activity for the period your surgeon recommends
A soft, easy-to-pass diet if the hernia was perineal
Monitoring the incision for swelling, discharge, or odor
Recheck visits to confirm healing

Recurrence is a real risk with perineal hernias. In one study, 15 percent of dogs had the hernia come back and 7 percent developed a surgical site infection [9]. Timing of neutering and postoperative fecal incontinence both raised the recurrence risk [9].

For hiatal hernia, the goal after surgery is fewer gastrointestinal signs and less need for ongoing medication [5]. Some dogs still need diet changes or drugs long term.

Prevention

You cannot prevent every hernia, but you can lower the odds:

Use a seat belt or crate in the car. Car trauma is a leading cause of diaphragmatic hernia [1][4].
Ask about breeding dogs with a history of umbilical hernia. A hereditary cause is suspected [2].
Fix hernias when they are small. Repair lowers the chance of intestine getting trapped later [2].
Treat constipation and straining early, especially in older male dogs, since straining raises pressure inside the belly.
Keep routine vet visits so small lumps get checked before they change.

If your dog has a lump near the rear end or is straining to poop, our guide to Dog Ear Infection Symptoms is not the right match, but a vet visit is. Rear-end lumps are easy to confuse with anal gland problems, so let a professional look.

Limitations and When to Contact a Veterinarian

No article can tell you whether your dog's specific lump is safe. Only a veterinarian who examines your dog can do that.

Go to an emergency clinic now if you see:

Labored or rapid breathing, especially after a car accident or fall [1]
A bloated, tight abdomen with retching or unproductive vomiting [1]
A hernia lump that is firm, hot, discolored, or very painful
Collapse, pale gums, or a dog who will not stand

Call your vet the same day if you see:

A new lump in the groin, belly, or beside the anus
Vomiting that keeps coming back [6]
Straining to poop or ribbon-like stools
A lump that used to push back in and no longer does

Bring it up at a routine visit if:

Your puppy has a small, soft umbilical hernia that has not changed
Your dog has a known hernia and no signs of trouble
You are planning a spay or neuter and want the hernia fixed at the same time

Frequently Asked Questions

Is a hernia in dogs dangerous?

It can be. A hernia that traps intestine cuts off blood flow and can become life-threatening within hours, and a diaphragmatic hernia can cause fatal breathing problems [1]. A soft, reducible hernia with no other signs is usually not an emergency, but it still needs a vet visit.

Can a hernia in dogs go away on its own?

Small umbilical hernias in puppies sometimes close as the puppy grows, but many do not. Surgical closure is recommended in most cases to lower the risk of intestine getting trapped later [2]. Your vet can tell you whether watching and waiting is reasonable for your dog.

How do I know if my dog's hernia is strangulated?

The lump becomes firm, painful, and impossible to push back in, and your dog may vomit, drool, or act depressed. A trapped stomach can bloat and the dog's condition can worsen rapidly [1]. These signs mean emergency care right away.

Are hernias in dogs painful?

A simple, reducible hernia is often not painful at all. A strangulated hernia is painful, and a diaphragmatic hernia can cause severe breathing distress [1]. If your dog flinches when you touch the area or is panting at rest, treat it as urgent.

Can a hernia come back after surgery?

Yes, especially perineal hernias. In one study, 15 percent of dogs had a recurrence after perineal hernia repair [9]. Neutering before the repair and fecal incontinence after surgery both raised that risk [9]. Follow your surgeon's aftercare instructions closely to lower the chance.

References

Diaphragmatic Hernia in Dogs - Dog Owners. Merck Veterinary Manual.
Hernias in Animals - Digestive System. Merck Veterinary Manual.
Minimally invasive glove port hernioscopy in a female dog with an intermittent hernia and abdominal mass: A case report. Research in veterinary science, 2026.
Diaphragmatic Hernia in Animals - Respiratory System. Merck Veterinary Manual.
Comparison of outcomes in dogs undergoing hiatal hernia repair with and without use of a gastropexy: 41 cases (2012-2022). The Journal of small animal practice, 2025.
Canine pleuroperitoneal diaphragmatic hernias: a multicentric, retrospective, observational analysis of 20 dogs (2009-2026). The Journal of small animal practice, 2026.
Case report: Diagnosis and surgical treatment of delayed traumatic diaphragmatic hernia with hepatothorax and enterothorax in a small dog. Frontiers in veterinary science, 2024.
Traumatic dorsolateral diaphragmatic hernia in a juvenile raccoon dog (Nyctereutes viverrinus viverrinus). The Journal of veterinary medical science, 2026.
Dogs neutered prior to perineal herniorrhaphy or that develop postoperative fecal incontinence are at an increased risk for perineal hernia recurrence. Journal of the American Veterinary Medical Association, 2025.