A peritoneopericardial diaphragmatic hernia, or PPDH, is a defects that can develop in utero. They do not commonly happen in cats, but are the most frequently occurring problem of the pericardial cavity that cats experience. This defect manifests as a hole in both the diaphragm and the pericardium (the sac that contains the heart). The abdominal organs can pass through these holes and cause serious heart issues. 

The first indication that a cat has a PPDH may be labored breathing. Symptoms may progress to anorexia, inability to withstand activity, shock, and even collapse. If the cat's blood is tested, many abnormalities may be present. When listened to with a stethoscope, the heart will likely sound muffled. X-rays will reveal an enlarged heart. Symptoms most often occur in cats with a large defect. Small defects may not cause issues for the affected animal at all. If symptoms have developed, surgical repair will likely be needed. This repair will need to be performed by an ACVS board-certified veterinary surgeon.

Before surgery is attempted, blood work will be run to determine if the cat will be able to survive the use of general anesthesia. An electrocardiogram may be used to see how drastic the abnormalities of the heart rate are. X-rays will be taken to confirm the location and severity of the hernia. Once this information has been collected, the veterinarian will be able to decide whether surgery is necessary.

If a surgical repair is performed, the animal will likely be medicated with atropine initially. Manual ventilation may be used throughout the procedure. An incision will be made from the chest through to the pericardial cavity. Any misplaced organs will be manually pushed back through the diaphragm to the abdominal cavity. If deadened tissue exists, it will have to be removed. Some organs may be twisted, or may need to be cut free from surrounding tissue. The opening should be closed shut with sutures so that organs can no longer pass through to the pericardial sac. All air should then be removed from the sac and the chest incision should be sutured or stapled shut. 

In cats who have developed complications due to PPDH, surgical repair is generally the only treatment available. This surgery is an effective way to treat or prevent heart failure from occurring or to save the abdominal organs from torsion damage. The overall prognosis for this procedure is excellent, with cats expected to make a full recovery and live a normal life-span.

The cat should be monitored in the immediate hours following the operation for any vomiting or difficulty breathing. This can be an indication of more serious problems and should be reported to the surgeon immediately. Pain relief will be administered after the surgery, continuing for up to a week after the procedure has taken place. Regular meals can resume the same day as the surgery. 

A follow-up appointment will be scheduled in the two weeks following the repair. Any staples or sutures will be removed at this time. New blood tests will also be run to verify if the abnormalities have resolved following the procedure. X-rays should be taken 3 months after surgery to ensure the heart is returning to the appropriate size and that all organs have stayed in place. Another check up will be performed six months post-surgery.

As this surgery involves many vital organs and must be performed by an accredited veterinary surgeon, the price is generally high. The procedure may range in cost from $2,000 all the way up to $6,000. The average price for a standard peritoneopericardial diaphragmatic hernia repair is $2,500. If the defect is small and no adverse symptoms are occurring, no treatment may be needed. 

Serious complications from a PPDH repair are very rare and usually minor if they do happen. Older cats may be more likely to develop issues from the procedure. The organs involved may be damaged by the intervention. Hypertension may develop, along with myelolipomas of the liver and growths from the pericardium wall to the organs. Overall, this surgery is low in risk and is usually associated with excellent outcomes.

As PPDH is a birth defect, it is very difficult to prevent it from developing. PPDH is often paired with other defects such as umbilical hernia, deformations of the heart, hydrocephalus, pulmonary vascular disease, and hair swirling on the abdomen. Many times these defects are not found until a routine x-ray or ultrasound is being taken for another purpose. In some instances, defects are not seen until autopsy. Chronic issues involving breathing or digestive problems may be first signs of PPDH complications. To prevent injury causing diaphragm and pericardium damage, keeping your cat indoors can prove to be very effective.