What is a hiatal hernia?
A hiatal hernia occurs when the upper part of the stomach, called the cardia, pushes through the natural opening in the diaphragm called the esophageal hiatus. During a hiatal hernia, part of the stomach is therefore found in the thoracic cavity instead of being in the abdominal cavity.
There are several types of hiatal hernia and we distinguish as follows:
- Type 1 hiatal hernia in which the junction between the esophagus and the stomach and part of the stomach slip through the esophageal hiatus. This is the most common type of hiatal hernia.
- Type 2 hiatal hernia or paraesophageal hiatal hernia where only the fundus of the stomach (upper stomach) or another abdominal viscus passes through the diaphragm without displacement of the junction between the esophagus and the stomach that remains in the abdominal cavity.
- Type 3 hiatal hernia when type 1 and 2 hernias are associated.
- Type 4 hiatal hernia which is a type 3 hernia complicated by the passage of other organs through the natural orifice of the diaphragm.
What causes a hiatal hernia in dogs?
In some cases, hiatal hernia is a congenital anomaly, present from the birth of the animal. And, although all dog breeds can be affected, some dog breeds seem to be predisposed to it. This is particularly the case for brachycephalic breeds such as the Shar Pei, the English Bulldog, the French Bulldog, the Chow Chow, the Boston Terrier and the Pug.
Hiatal hernias can also be acquired as a result of chest or abdominal trauma or during obstructive respiratory syndrome which affects brachycephalic races.
What are the symptoms of a hiatal hernia?
The most common symptoms associated with hiatal hernias are vomiting and excessive salivation (or ptyalism). Affected dogs can also suffer from regurgitation, coughing, anorexia and suffer from weight loss and breathing difficulties often linked to pneumonia by false swallowing.
When the hiatal hernia is congenital, the symptoms appear before the age of one year and can even sometimes coincide with weaning, around the dog's 2 months.
How is a hiatus hernia diagnosed?
Diagnosis is based on medical history, clinical signs and chest X-rays.Most dogs require a preparative x-ray that involves the ingestion of barite, to demonstrate the hernia. Esophagogastric endoscopy may also be performed.
How is a hiatus hernia treated?
Conservative medical treatment will usually be prescribed in dogs that do not require surgical treatment.
This medical treatment is based on:
- antisecretory drugs and proton pump inhibitors to control esophagitis and gastroesophageal reflux.
- antiemetics to calm vomiting,
- a special low-fat diet to promote gastric emptying.
Antibiotics are used as needed to fight any secondary infections, especially if aspiration pneumonia develops.
In severe or chronic cases that do not respond well to medical treatment, surgery is recommended. The techniques then vary according to the type of hiatal hernia. In brachycephalic dogs, it is usually necessary to surgically correct respiratory disorders before intervening on the hiatal hernia.