Diaphragmatic Hernia in Cats

A feline with a diaphragmatic hernia will be reluctant to exercise due to the effort it takes to fill the crowded lungs with air and will present signs of breathing difficulties.

A diaphragmatic hernia in cats is a tear or rupture in the diaphragm. The diaphragm is the sheet of muscle that separates the abdomen from the chest cavity. If that sheet of muscle becomes torn, the organs from the bottom half of the cat’s body push through into the chest cavity. The stomach, intestines, or liver may push against the cat’s lungs, making breathing very difficult for the cat. In other cases, the intruding organs crowd the heart, causing rhythm and auscultation abnormalities.

Symptoms of diaphragmatic hernia in cats depend on the severity and cause of the hernia. Classic clinical signs associated with diaphragmatic hernia include the following symptoms: 

• Muffled heart sounds
• Irregular lung sounds
• Lethargy 
• Exercise intolerance
• Tachypnea (increased respiration) 
• Dyspnea (shortness of breath) 
• Pale mucous membranes
• Labored breathing 
• Abnormal heart rhythm

In felines with a mild case of herniation, the cat may display the previously listed clinical signs for a few days. Symptoms may then disappear as the condition stabilizes. As the herniated tissues still remain, the symptoms can reappear upon physical activity or stressful situations. Depending on the organs affected by the cat’s diaphragmatic hernia, the feline may also suffer from:

• Coughing 
• Weakness
• Anorexia 
• Diarrhea 
• Vomiting 
• Abdominal distension 
• Pneumothorax (air in the chest cavity) 
• Hemothorax (blood in the chest cavity) 

Types

There are two types of diaphragmatic hernia in cats; congenital and traumatic diaphragmatic hernia. Although the term is synonymously used for both types, each should be considered separately, as the underlying causes differ greatly. 

Congenital

A congenital diaphragmatic hernia is present at birth likely caused by fetal development inside the womb. The most common type of congenital diaphragmatic hernia in cats is called peritoneal-pericardial diaphragmatic hernia (PPDH). 

Traumatic

A traumatic diaphragmatic hernia is caused by blunt force, tearing the diaphragm. 

The cause of a congenital diaphragmatic hernia in cats is the result of an undeveloped fetal diaphragm. Although present at the time of birth, the clinical signs of a diaphragmatic hernia may not present themselves until the feline reaches 1-2 years of age. 

Traumatic diaphragmatic hernias in cats are caused by blunt force, rupturing, tearing or bruising the muscle of the diaphragm. Common examples of blunt force linked to diaphragmatic herniation in feline includes: 

• Hard falls 
• Abusive trauma 
• Car accidents 

The diagnosis of diaphragmatic hernia in cats begins with careful physical examination conducted by the veterinarian. Your cat’s doctor will listen to her heart and lungs, tapping on the abdomen in addition to the chest for clinical signs suggestive of a herniated diaphragm. A definitive diagnosis will need to be made to prove the vet’s hypothesis, which is most commonly completed through x-rays of the chest and abdomen. Upon standardized radiography images, the images will reveal displaced abdominal organs and an irregularly shaped diaphragm if the feline does indeed have a herniated diaphragm. Your veterinarian may further his diagnostic examination by requesting a specialized x-ray that use dyes to highlight in intestine and stomach. Additionally, your cat’s doctor may request blood work from your cat, an electrocardiogram, fluid aspiration from the chest and perhaps a surgical exploration of the chest.

The only treatment available to cats with a diaphragmatic hernia is surgical repair, which should be performed once the cat is stable. To reach stabilization, the veterinary team may place the feline on oxygen therapy and intravenous fluids to restore hydration. If fluid on the lungs has been noted, a chest tap (thoracentesis) will likely take place to remove the crowding fluids off of the lungs and heart. The focus of the diaphragmatic hernia surgery itself entails repositioning the organs in their correct place and repairing the torn, or ruptured, diaphragm muscles. 

Your cat will require inpatient hospitalization following surgery in a time frame set by your veterinary care professional. Expect your feline to stay at least a day in the hospital as tubes are commonly placed in surgeries involving the chest cavity to avoid fluid accumulation. Pain management is the largest part of diaphragmatic hernia aftercare, so the doctor will likely administer pain drugs to the feline while she is in the hospital and send you home with a prescription. Once the feline is released, it is important for pet owners to restrict physical activity for a few days to prevent damage to the surgical site. Giving your cat a chance to rest will also speed up her healing time and make for a better recovery.