Hernia (Diaphragmatic) in Dogs

In dogs, the diaphragm separating the chest and abdominal cavity plays an important part in respiration and also acts as a barrier between the organs. If the diaphragm is torn or damaged, it allows the abdominal organs to protrude into the chest cavity. This is called a diaphragmatic hernia, or sometimes a diaphragmatic rupture. Hernias generally occur as a result of trauma to the abdomen, but some dogs can be born with an incomplete diaphragm due to abnormal development of the fetus. The most typical form of congenital diaphragmatic hernia is Peritoneal-Pericardial Diaphragmatic Hernia which can affect the pericardial sac surrounding the heart. Any diaphragmatic hernia can be a very serious and life-threatening condition. Migration of the abdominal organs into the chest cavity can cause severe breathing difficulty and abnormal heart rhythms. Some dogs may have milder symptoms that go unnoticed and the hernia will develop into a chronic condition with fibrous attachments connecting the abdominal organs in a misplaced location. With chronic diaphragmatic hernia, dogs will suffer from repeated vomiting, weight loss, and liver disease. Most hernias can be treated surgically but ultimate recovery will depend on the immediacy of treatment and the extent of other injuries.

A rupture or tear in the diaphragm means the abdominal organs can migrate into the chest cavity where they will interfere with breathing. This is called diaphragmatic hernia. In dogs, this is most commonly caused by trauma to the abdomen, but it can also be congenital.

Getting treatment early is important, so watch for these signs in your dog.

• Breathing difficulties especially when upset or stressed
• Rapid or shallow breathing
• Vomiting
• Severe respiratory difficulty
• Muffled lung sounds
• Muffled heart sounds
• Abnormal heart rhythm
• Shock
• Abdomen that feels empty
• Weight loss or jaundice (chronic)

Types

Traumatic

• A diaphragmatic hernia or tear that is acquired from trauma
• The most common type of hernia in dogs, accounting for about 80% of cases

Congenital

• Any hernia that is inherited

Peritoneopericardial Diaphragmatic Hernia (PPDH)

• Most common type of inherited hernia that allows for communication between the abdominal cavity and the pericardial sac surrounding the heart
• Weimaraners and Cocker Spaniels are predisposed

Hiatal hernia

• Hernia around the esophageal connection
• More common in Shar Peis and brachycephalic breeds

Pleuroperitoneal hernia

• Rare in dogs

Traumatic and congenital hernias can be further characterized based on their symptoms.

Acute

• Severe symptoms that can be immediately life-threatening

Chronic

• An asymptomatic hernia that goes undiagnosed and develops into a long term condition

Congenital diaphragmatic hernias are inherited. Traumatic hernias are usually acquired from an accident that injures the abdomen.

• Falling out a window
• Car accident
• Blow to the abdomen

Diaphragmatic hernia will be suspected if your dog is showing symptoms of respiratory difficulty after a traumatic injury, especially one which affected the abdomen. Dogs that have suffered abdominal trauma should be examined regardless of whether they have symptoms since mild hernias that go unnoticed will become harder to treat. Any past traumas can also be relevant if your dog is showing symptoms of chronic gastrointestinal problems and liver disease. Breed and family history are important in diagnosing a congenital hernia; these will be more common in puppies although a mild congenital hernia could go unnoticed until later in life. Congenital hernias may often be combined with other abnormalities, such as a ventricular septal defect.

X-rays are the main tool for diagnosing a diaphragmatic hernia. The veterinarian may add a contrast dye to make the x-ray clearer. An ultrasound or CT scan may also be ordered to for a clearer picture of the abdomen and thoracic cavity. Blood and urine tests help to diagnose liver dysfunction in cases of chronic hernia.

If your dog has suffered an accident or trauma, you should assess him for immediate injuries and attempt to stop any bleeding. Try to keep the dog comfortable and avoid movement as much as possible during transportation. Cover the dog with a light blanket, but avoid anything that restricts breathing.

The veterinarian will attempt to stabilize your dog as much as possible before administering anesthetic for surgery. Severe cases may require emergency surgery if the abdomen fills with gas and your dog is unable to breathe. Surgery can be quite complex since the abdominal organs will need to be put back into position and the tear in the diaphragm will need to be sutured closed. If it is not an emergency, the veterinarian may refer you to a specialized surgeon. Your dog will need to stay in a veterinary hospital for some time after surgery so that the veterinarian can make sure the gastrointestinal and respiratory systems have returned to normal. This period could be extended based on other injuries. Intravenous pain medication may also need to be administered to make your dog feel better. After returning home, there will be a recovery period of reduced activity based on the veterinarian or surgeon’s recommendation. You may need to return for stitch removal, or a post-surgery check-up.

Diaphragmatic hernia can often be successfully treated with surgery, and your dog may make a complete recovery. Immediate treatment is very important however. Unfortunately, it’s estimated that about 15% of dogs with diaphragmatic hernias from trauma die before they can be treated. Other complications, like additional injuries or several congenital defects, can greatly affect your dog’s prognosis. If the condition is chronic and fibrous connections have developed around the abdominal organs, this will make it much harder to separate and reposition the organs without damage. Your dog’s chances of recovery can be determined more accurately by a veterinarian upon diagnosis.