Cat - Rupture of the Diaphragm

The diaphragm is the muscular sheet which separates the chest cavity from the abdominal cavity and is important in breathing movements. If it becomes ruptured, organs from the abdominal cavity may pass through the tear to enter and lie within the chest cavity next to the heart and lungs.  This can cause life threatening breathing difficulties.

Causes of rupture of the diaphragm

Rupture of the diaphragm results from an accident most often a road traffic accident. If a car wheel runs over the body, the diaphragm is very vulnerable to rupture due to the pressure created. Occasionally other forms of accident can lead to ruptured diaphragm such as falling out of a tree.

Signs of ruptured diaphragm

The main sign of rupture of the diaphragm is difficulty in breathing often with very exaggerated breathing movements of the chest. This is partly because the diaphragm is important in breathing movements but also because abdominal organs pass into the chest cavity and compress the lungs. There may be other signs of a recent accident such as abrasions, and bruises and torn claws but sometimes there may be no external signs of injury and the owner may not realise that their cat has been involved in an accident. Some cats do not show breathing problems and the hernia is diagnosed during investigations for other reasons.

Diagnosis of ruptured diaphragm

There are a large number of possible causes of difficulty in breathing, particularly after an accident. There may be clues as to the cause of breathing difficulty on examination of the cat, particularly auscultation (listening with a stethoscope) of the chest, but confirmation of a ruptured diaphragm will require a chest x-ray and sometimes an ultrasound scan.

Treatment

Surgical correction of the tear is required for treatment of ruptured diaphragm. This can be tricky surgery and particular care is needed for anaesthesia. The tear is usually approached through an incision in the abdomen. Since the tear results in the abdominal and chest cavities being connected, as soon as the abdominal incision is made, the negative pressure (vacuum) within the chest is lost and it is necessary to artificially ventilate the patient until the tear has been repaired. Although the surgery can be difficult, if this is successful the cat will usually make a full recovery.