Hiatal Hernia in Dogs

What are hiatal hernias?

A hernia occurs when one part of your body, or part of an organ, protrudes through a gap or opening into another part of the body. Many types of hernias occur in the abdominal area. Hiatal hernias form at the opening (hiatus) in the diaphragm where the esophagus (the tube that carries food to the stomach) joins the stomach. Hiatal hernias are a form of diaphragmatic hernia.

When the muscle tissue around the hiatus becomes weak, the upper part of the stomach may bulge through the diaphragm into the chest cavity. Hiatal hernia refers to the protrusion of the abdominal contents into the chest cavity through the esophageal hiatus of the diaphragm. They are graded as types 1 to 4. Type 1 is the most common and involves the abdominal portion of the esophagus and upper part of the stomach; type 4 is the most severe and often involves the intestines and or other abdominal organs; this type is very rare in dogs.

What causes a hiatal hernia?

In most veterinary patients, hiatal hernias appear to be a congenital (or birth) defect. The Bulldog and Chinese Shar-Pei seem to have a higher incidence of hiatal hernias than other breeds, although any breed can be affected. Male dogs are thought to be at greater risk for having a hiatal hernia.

Acquired hernias can also occur in dogs. Typically, these are due to increased pressures inside the abdomen due to chronic vomiting, or decreased pressures inside the chest due to airway obstruction.   Brachycephalic dogs (short-nosed breeds) are at higher risk due to their anatomy. Trauma rarely leads to a hiatal hernia; a diaphragmatic hernia is the more likely result.

What are the clinical signs of hiatal hernia?

Many dogs that have small hiatal hernias have no accompanying clinical signs. The signs most associated with hiatal hernias include vomiting, regurgitation, excessive salivation, blood in the vomit and difficulty breathing. These signs are more often to occur during excitement and/or exercise.

How is a hiatal hernia diagnosed?

Diagnosis is based on medical history, clinical signs, and X-rays (radiographs). Most dogs will require a special radiographic dye study or contrast fluoroscopy for a definitive diagnosis. Esophagoscopy and gastroscopy may also be performed.

How is a hiatal hernia treated?

Conservative medical treatment will usually be recommended for those with mild signs. Medications to help control reflux and esophagitis are used at the start of treatment. Acid-blocking medications, for example omeprazole (brand names Gastrogard® and Prilosec®) and/or medications to promote stomach emptying, for example cisapride (brand names Prepulsid® and Propulsid®) or metoclopramide (brand name Reglan®) may be prescribed. Antibiotics are used as needed to combat any secondary infections, especially if aspiration pneumonia develops. In severe or chronic cases, surgery is recommended.

What is the prognosis for a dog diagnosed with a hiatal hernia?

The prognosis for hiatal hernia is guarded. Many dogs will develop secondary conditions such as aspiration pneumonia. Your veterinarian will be able to give you a better prognosis based on your pet's specific condition and clinical signs.