Umbilical hernia in dogs

Overview

What lies beneath the navel?

An umbilical hernia leaves an opening, or hernial ring, in the abdominal wall at the navel. Tissue protrudes from the abdominal cavity into a sac beneath the skin. This can contain fat alone or omentum, the fatty tissue covering abdominal organs. A sufficiently large opening can also admit a bowel loop.

A reducible hernia allows contents to move back into the abdomen. Irreducible contents may adhere to the opening's edges. Some small fat-containing hernias remain stable and asymptomatic.

UK primary care records noted umbilical hernia in 0.93% of dogs in 2016. There were 208 recorded cases.

The navel lies on the underside just behind the chest. Abdominal wall hernias are named by location. Inguinal hernias occur in the groin, whereas umbilical hernias lie on the midline.

Causes

Closure of the puppy's umbilical ring

Before birth, umbilical blood vessels pass through a ring in the foetal abdominal wall. A hernia develops if this ring fails to close completely after birth. The opening lets fat pass between abdominal muscles beneath the skin. The precise cause is not known for every case. Greater frequency in some family lines suggests inherited susceptibility.

Umbilical circulation supplies nutrients before birth. Sometimes a small fat tag remains beneath skin even when the opening closes later.

The navel remains where the cord detaches after birth. Protruding tissue can prevent wall closure in newborns. Congenital umbilical hernias usually pass through the ring formed during foetal life. A traumatic abdominal wall hernia instead forms at a rupture.

Risk factors

Hernias are often detected at initial puppy appointments. They have been reported more often in breeds such as Weimaraners and Basenjis. Some affected males also have an undescended testicle. UK primary care records in 2016 noted hernias in 3.9% of Shih Tzus.

Among female Shih Tzus, 4.8% had a recorded hernia. The male proportion was 3.0%. The adjusted diagnosis odds ratio in UK brachycephalic dogs was 3.16 compared with other dogs.

One kennel club health survey from northern Europe recorded hernias in 7.1% of Wire-haired Dachshunds with responses. Severe hernias requiring surgery are rare in Dachshunds. One Finnish Lapphund breeding committee knew of 235 cases when preparing its current programme. These are reported cases and cannot establish prevalence across all Finnish Lapphunds.

Median age among Shih Tzus with a recorded hernia was 1.4 years. Across UK dogs with recorded hernias, median age at the end of 2016 was 1.03 years.

Typical symptoms

A typical hernia feels soft. It is usually not tender. Visibility can change as contents move with body position.

• A bulge is visible or palpable beneath navel skin.
• It may be clearer while standing.
• It may briefly disappear while lying on the back.
• Straining can make it more visible in puppies.
• Trapped tissue can make it painful.

A small, longstanding fat lump can be firm yet painless.

Strangulation can cause sudden severe pain around the navel. Bowel obstruction can reduce appetite. Severity depends on the degree of obstruction. Vomiting may be less marked with obstruction near the end of the small intestine.

Complications and consequences

Trapped bowel and impaired blood flow

Rarely, bowel can become trapped in the ring. A trapped loop can obstruct passage of food and intestinal contents. Strangulation compresses blood supply, reducing or stopping it. Loss of supply can kill bowel tissue. Strangulation needs urgent surgery.

Persistent obstruction accumulates fluid and gas upstream. Profuse vomiting can dehydrate dogs. A damaged bowel wall can perforate. Bacteria can pass from intestinal contents into injured tissue at a strangulated segment.

Venous drainage may be blocked first in compressed bowel. Congestion can deprive tissue of oxygen. Sudden loss of bowel blood supply can rapidly cause circulatory shock. Perforation can cause bacterial peritonitis. After intestinal surgery, peritonitis increases suture-line failure risk.

Intestinal suture failure most commonly occurs three to five days after surgery. It usually needs another operation.

Diagnosis at the vet

Feeling the lump and opening

A clinical examination can usually identify the hernia. The vet feels the sac beneath the skin. Opening size is assessed separately. Examination establishes whether contents return to the abdomen. Findings are particularly clear when contents can be moved back through the opening. Whether bowel can pass through influences the surgery decision.

Ultrasound and X-rays for suspected complications

Ultrasound can investigate suspected complications. It can also seek abdominal fluid when bowel injury is suspected. Fluid- or gas-distended loops can indicate complete obstruction on X-rays. Abdominal fluid may be sampled for bacterial peritonitis.

Free abdominal gas can suggest perforation during bowel injury assessment. Gas within bowel can impair ultrasound visibility. Electrolytes can change with hernia-related obstruction.

Fluid leaking from the navel

Discharge present from birth can indicate a rare congenital anomaly. An abnormal connection to bile ducts can leak bile through the navel. Ultrasound and contrast CT can locate it. Contrast bladder imaging can investigate a suspected patent urachus, a persistent foetal urinary connection.

Treatment

When is monitoring enough?

Very small, asymptomatic fat-containing hernias can be monitored if not growing. Some small hernias close spontaneously by three to four months. Openings wide enough for bowel passage require surgical repair. A hernia growing with the puppy also warrants surgical assessment.

Planned repair

An asymptomatic persistent hernia can be repaired during neutering if waiting is considered safe. Repair requires general anaesthesia. Vital functions are monitored throughout. The vet makes an incision over the navel. Viable contents return to the abdomen. The wall opening is sutured closed. Surrounding scar or connective tissue may be removed. Adherent abdominal tissue may need freeing before closure. Skin can be closed with absorbable or removable sutures.

Prognosis after routine repair is good. Recurrence is rare.

Closing the ring reduces later bowel entrapment risk at that site.

One clinical case from northern Europe described a puppy with a large, soft hernia detected at its first vaccination visit and repaired electively because bowel could pass through. A thin tissue layer can be removed from the ring margins before suturing.

Emergency strangulation surgery

The surgeon assesses viability of trapped bowel. Obstruction-related dehydration is corrected before surgery where possible. Electrolyte balance can be corrected before anaesthesia if circumstances allow. Dead bowel may need removal. Remaining healthy ends are then joined. Bacterial peritonitis can require post-operative antimicrobials.

Prevention

Some breeding guidance for Wire-haired Miniature and Rabbit Dachshunds excludes severe hernias even after surgery. A small hernia alone does not preclude breeding under this guidance. It advises against combining two lines with hernias.

Some Finnish Lapphund breeding guidance advises excluding dogs with hernias needing surgery or already repaired. Some Saluki guidance advises against mating two affected dogs. It also advises excluding bitches with hernias requiring surgery.

Important for dog owners

Home monitoring and wound care

When monitoring is advised, watch for changes in lump size during growth. Note whether visibility varies with position or movement. Routine surgical recovery often takes 10–14 days. Keep walks short and on-lead according to discharge instructions. Avoid jumping and rough play to prevent wound edges tearing. Prevent licking with a collar or recovery suit. Check the wound daily. Promptly report discharge or marked redness.

Leave palpation to the vet because pressing can harm a serious hernia. Removable skin sutures usually come out at 10–14 days. Contact the surgeon for pain despite prescribed relief.

Tell the breeder about a puppy's hernia because some family lines are more affected. Wound protection also prevents suture damage. The vet can check healing during suture removal.

Frequently asked questions

Can a puppy's navel lump disappear?

Small hernias may close by three to four months. Fat left outside during closure can leave a small lump. Palpation can establish whether an opening remains.

Why is the hernia sometimes more visible?

Contents can move through the opening with changing position. Standing can push them more clearly beneath skin. Straining can temporarily accentuate a puppy's bulge. Barking can do the same.

Does a firm lump always mean an emergency?

A small, longstanding unchanged lump can be a painless fat-containing hernia. Call an emergency clinic immediately for sudden hardening and tenderness of a previously soft lump. Sudden heat can also suggest trapped tissue.

Can repair be combined with another operation?

Yes, persistent hernias can be repaired during neutering. The vet first assesses whether opening size favours earlier repair. Threatened bowel circulation needs urgent surgery. Trapped bowel can become necrotic.

When should I call about the surgical wound?

Promptly report marked swelling or discharge. Check the area daily to detect changes early. Use a protective suit or collar as instructed.