Hernias in Dogs

Key Takeaways

A hernia is a swelling caused by abdominal contents bulging out due to a defect in the surrounding muscles.

• Most hernias are either present at birth or result from injuries

• In serious cases the abdominal contents become trapped, cutting off the blood supply to the affected area

• Strangulating hernias are firm and painful and the surrounding skin may be discolored and are an emergency

• In a diaphragmatic hernia, abdominal contents are drawn into the chest cavity, which are commonly the result of blunt-force trauma (like being hit by a car), and can cause life-threatening respiratory distress

• Investigation of hernias focuses on physical examination and diagnostic imaging

• Small  hernias may not require treatment whereas large, strangulating, or diaphragmatic hernias require emergency surgical repair

• Prognosis varies depending on the location and severity of the hernia

A Closer Look: What are Hernias in Dogs?

In many cases, hernias present as a doughy bulge under the skin which is not painful on palpation. Diaphragmatic hernias relate to a hole in the diaphragm and are not palpable externally.

Symptoms specific to individual hernias include:

• Gastric reflux and regurgitation in cases of hiatal hernias

• Breathing difficulties in cases of traumatic diaphragmatic hernias, including labored breathing, rapid breathing, and collapse Note: these symptoms are always an emergency requiring immediate veterinary care

• Straining to defecate in perineal hernias

• Straining to urinate in some cases of inguinal hernias

In cases of minor hernias, the soft, non-painful swelling can often be reduced if the dog is relaxed and gravity pushes the abdominal contents back into the body cavity.

Risk Factors

The severity of hernias in dogs varies significantly by location in the body, size, and cause. A small, congenital umbilical hernia often requires no treatment whereas an acquired strangulating hernia or diaphragmatic hernia can be fatal.

Possible Causes

Hernias are either congenital or acquired. Congenital hernias are present at birth and are usually hereditary. The most common example is an umbilical hernia. Other locations include inguinal, perineal, and diaphragmatic.

Acquired hernias result from injuries, or weakening of the body wall as seen in some hormonal conditions. Acquired hernias, also known as ruptures, occur either in the same location as congenital hernias, or any other part of the abdominal wall.

Main Symptoms

Symptoms of hernias vary depending on the location and cause. Common symptoms of non-strangulating hernias include: 

• A soft swelling that is usually palpable or visible. The most common areas are:

◦ Umbilical - Middle of the abdomen ◦ Inguinal - Inner thigh on one or both hind legs ◦ Perineal - either side of the anus

Symptoms of strangulating hernias include:

• Firm, painful swelling • Red to blue/black discoloration of the affected area • Abdominal pain • Collapse

Testing and Diagnosis

Diagnosis of hernias involves:

• Physical examination • Diagnostic imaging x-ray, ultrasound, CT scan • Laboratory testing

Steps to Recovery

Treatment of hernias depends on location and severity. 

• Surgical repair of the hernia

• Hernia-specific treatment such as castration in the case of perineal hernias

• Medication such as pain relief or antacids

Most hernias in dogs are easily corrected surgically and have a good prognosis. Some minor hernias do not require treatment and may be monitored indefinitely. Rare cases of strangulating hernias, or severe diaphragmatic ruptures, require extensive treatment, and are sometimes fatal.

Prevention

Some hernias are inherited. These dogs should not be bred to reduce inheritance. Female dogs are more prone to inguinal hernias after giving birth. Male dogs are more prone to perineal hernias if they are uncastrated. Neutering in male and female dogs reduces the incidence of these hernias. General environmental management to reduce the likelihood of severe traumatic injury helps to prevent more serious acquired hernias.

Are Hernias Common in Dogs?

Umbilical hernias are the most common type in dogs and occur in ~0.2% of puppies. Other types of hernia are rare and usually seen in association with other diseases or injuries

Typical Treatment

Treatment of hernias includes

• Surgical closure • Treatment of underlying causes • Sexual alteration (spay/neuter) • Fluid therapy • Exploratory surgery