Diaphragmatic Hernia in Dogs

Overview of Canine Diaphragmatic Hernia

The diaphragm is the muscle that separates the abdominal organs from the heart and lungs, and when the diaphragm contracts, air enters the lungs. A defect in the diaphragm allows abdominal organs such as the liver, stomach and intestines to enter the chest cavity. These organs then sit in the space between the lungs and the body wall and can compress the lungs, making it difficult for them to expand normally. This can cause difficulty breathing. However, some animals may only exhibit vomiting or other signs related to compromise of the organ that has herniated into the chest. Some animals show no signs related to the hernia and it is only noted on physical examination, when radiographs are taken, or at surgery.

Diaphragmatic hernias may be either congenital, which are present at birth due to abnormal development of the diaphragm, or traumatic, which are a result of an injury such as being hit by a car, falling from a height or being kicked. The latter is more common.

What to Watch For

Signs of diaphragmatic hernia in dogs may include:

• Difficulty breathing
• Rapid breathing
• Coughing
• Exercise intolerance

Other symptoms that can occur depending on what organs are trapped in the chest include:

• Vomiting
• Difficulty eating
• Constipation
• Diarrhea
• Not eating at all (anorexia)
• Abdominal distension
• Weight loss
• Collapse
• Shock

Diagnosis of Diaphragmatic Hernia in Dogs

Diagnostic tests are needed to recognize a diaphragmatic hernia. Tests may include:

• A complete medical history and physical examination
• Radiographs (X-rays) of the chest and abdomen
• Abdominal ultrasound to determine if abdominal organs are in the chest and to note tears in the diaphragm
• Blood tests, especially if your pet has been hit by an automobile, had other trauma, or is obviously ill and is vomiting, collapsed, or in a state of shock

Treatment of Diaphragmatic Hernia in Dogs

• Emergency stabilization of your pet may be necessary if he has been hit by a car or had other trauma. This may include intravenous (IV) fluids, steroids, antibiotics or other medications.
• Oxygen therapy may be recommended
• Sometimes it is helpful to keep the animal’s front-end elevated to allow gravity to push the abdominal organs back.
• Once your pet is stable, often at least 24 hours after the trauma, surgical repair of the hernia is done.

Home Care

To reduce the likelihood of your pet developing a traumatic diaphragmatic hernia, keep your dog on a leash. The most common cause of diaphragmatic hernia and other very serious injuries is trauma caused by a motor vehicle accident.

Contact your veterinarian immediately if your pet has been injured or if you notice any abnormal signs.

In-depth Information on Diaphragmatic Hernia in Dogs

There are several causes of diaphragmatic hernia. They include the following:

Congenital Causes

Abnormal development of the diaphragm occurs for unknown reasons during gestation and prior to birth. Typically the hernia is between the abdominal cavity and the sac that contains the heart (pericardium). Abdominal organs can enter the pericardium and cause fluid accumulation within it and around the heart. The herniated organs and the fluid around the heart can impair function of the heart and lungs; however, many animals have this condition without any symptoms at all. In these animals the hernia may be found unexpectedly when X-rays of the chest are taken for some other reason.

Animals with symptoms may have the following clinical signs:

• Vomiting
• Diarrhea
• Constipation
• Difficulty breathing
• Rapid breathing
• Coughing
• Poor appetite or not eating at all
• Weight loss
• Abdominal distension from fluid accumulation
• Exercise intolerance
• Shock or collapse

Traumatic Causes

Animals that have been hit by a car, kicked, or have fallen from a height can get a tear in the diaphragm caused by an increase in pressure in the abdomen. They can also get a tear from a direct injury caused by a gunshot wound or a stabbing injury. Symptoms that an animal with a traumatic hernia might have are similar to those mentioned above for a congenital hernia, but in addition they are more likely to be in shock. They may also have other evidence of trauma, such as bleeding into the lungs or chest cavity, bruising of the lungs (pulmonary contusions) and fractures). As with congenital hernias, some animals seem normal and the diaphragmatic hernia is an unexpected finding.

In-depth Information on Diagnosis

Diagnostic tests are needed to recognize a diaphragmatic hernia in dogs. Tests that your veterinarian may wish to perform include:

• A complete medical history. You will usually be asked specific questions regarding your pet’s appetite, weight loss or gain, urination, defecation and breathing pattern. Your veterinarian will also want to know if your pet has been outside unsupervised, allowing an opportunity for injury.
• A complete physical exam. Your veterinarian will listen to your pet’s heart and lungs and palpate (technique of checking parts of the body by touching and feeling them) his abdomen. If there is a diaphragmatic hernia, the heart and lung sounds will be abnormal and the abdomen may feel abnormal. If your pet has collapsed and has pale gums, he may be in shock.
• Diagnostic imaging. Radiographs (X-rays) of the chest are often taken whenever an animal has been hit by a car or suffered other types of major trauma. These X-rays can reveal many types of injuries to the chest wall, lungs and heart, including diaphragmatic hernias. As with many diseases, early detection often leads to improved results. On a chest X-ray of a patient with a diaphragmatic hernia, the abdominal organs may be seen in the chest cavity, surrounding the heart and lungs. An ultrasound of the chest and diaphragm is helpful if a diaphragmatic hernia is suspected but abdominal organs were not visualized in the chest on the X-ray.
• Blood tests. If an animal has suffered a major trauma, is vomiting, has diarrhea, has collapsed or is in shock, blood tests are important in determining the underlying problem. Blood tests can often hint at the type of injuries that have happened to your pet’s abdominal organs, show the levels of the major body electrolytes, indicate if there was major blood loss or reveal if your pet has a blood clotting problem (bleeding disorder). This information is necessary in directing your veterinarian in providing life-saving therapy and determining the appropriateness and need for various medications, blood transfusions or emergency surgery.

In-depth Information on Treatment

Treatments for diaphragmatic hernia may include the following:

• Stabilization. If your pet has suffered a major trauma, emergency measures may need to be taken to stabilize him before surgery can be considered to repair the diaphragm. Emergency treatments including intravenous (IV) fluids, blood transfusions, steroids, antibiotics and oxygen are among the most common treatments used in a critical trauma patient. Each patient is different and may require different therapies. Anesthesia for surgery can be more safely administered after your pet is stable, which often takes at least 24 hours. Very rarely, an animal cannot be stabilized and has to have immediate surgery to repair the hernia. Most often this is because the organs are pressing on the lungs to such an extent that the lungs cannot inflate properly, or because the stomach has herniated into the chest and has distended causing difficult breathing and low blood pressure.
• Surgery. For surgery your pet will be anesthetized and placed on a ventilator to help him breathe. The hernia is repaired by making an incision in the abdomen, pulling the displaced abdominal organs out of the chest, returning them to their normal positions and closing the defect in the diaphragm. Sometimes the organs that were herniated, such as the liver, spleen or intestines, may have had their blood supply damaged, necessitating partial or total removal. A tube may be placed in the chest cavity to drain air and fluid out of the chest after surgery. Your pet will be monitored closely after surgery for evidence of difficulty breathing or other problems.
• Prognosis. Statistics on pets with congenital diaphragmatic hernias show about an 80 to 85 percent survival rate after surgery. Animals with traumatic diaphragmatic hernias have a more guarded prognosis, probably due to injuries to other major organs at the time of the accident. Statistics on these patients range from 52 to 88 percent survival rate.

Follow-up Care for Dogs with Diaphragmatic Hernia

Congenital Hernias

There is no way to prevent congenital diaphragmatic hernias, which are developmental malformations, from occurring in a particular dogl; however, it is recommended that affected dogs not be used for breeding purposes because this condition may be hereditary.

Be observant and know what your pet’s normal breathing pattern is. Being familiar with what is normal allows you to notice subtle changes and help diagnose problems early.

The symptoms associated with a congenital diaphragmatic hernia are vague and non-specific. If you suspect that your dog might have a diaphragmatic hernia, X-rays may be a helpful screening test.

Traumatic Hernias

Traumatic diaphragmatic hernias can be prevented. Protect your dog from potential trauma by keeping him or her out of dangerous situations. Dogs should be kept on a leash when not confined to a house or fenced yard. Even the most obedient dog will sometimes chase another animal or car, despite your commands. Be particularly vigilant when your dog is around horses or cattle that might kick them.

Contact your veterinarian as soon as you notice your dog has any abnormal breathing patterns, vomiting, diarrhea or any of the previously mentioned symptoms that can be associated with a diaphragmatic hernia.