If you notice a lump on your cat's belly after abdominal surgery, you may be worried that it's a hernia. While a cat hernia after being spayed is possible, swelling on your cat's stomach could be a number of other things — but there's usually no reason to worry.

Read on to learn more about the different kinds of hernias, other reasons for abdominal lumps and bumps in cats, and when to seek veterinary care.

What Is a Cat Hernia?

According to the Merck Veterinary Manual, hernias of the abdominal wall are common in all domestic species, and cats are no exception. Hernias are defects, or holes, in the walls within the cat's body that separate one part from the other. An example of one of these "walls" is the abdominal wall that keeps your cat's abdominal organs in place and separate from tissue and fat directly underneath the skin. Hernias are often classified by location, including:

• Umbilical hernias: These range in size from barely detectable to quite large. They may contain fat from the cat's belly cavity, or in more severe cases, intestines. The most commonly seen hernia in cats, these occur when the abdominal wall has a hole in it. They may be discreet, but when the cat stands on all fours, a bubble-like swelling may appear as fat or intestines from the abdomen move into this "pocket."
• Inguinal hernias: Also known as scrotal hernias, these are less common in cats and involve a hole through the abdomen through a small canal in the groin area. Inguinal hernias can occur in both females and males.
• Diaphragmatic hernias: Even more rare, there are several hernias that can occur between the abdomen and chest cavity by the diaphragm. They are often seen in kitties that have been hit by a car, though some cats may be born with them.

Hernias can vary in severity but are often congenital, or present at birth, especially in kittens. According to a journal in VetRecord, there is a genetic and developmental basis for umbilical hernias in cats, as well as dogs. Alternatively, hernias can occur at various points throughout a cat's life. Traumatic hernias may be caused by events such as a difficult birth or a physical trauma. In some cases, a hernia can develop after surgery.

Diagnosing and Treating a Cat Hernia

Hernias are easily diagnosed as your veterinarian will usually be able to feel the defect and gently replace the contents that have shifted into their hernia's "pouch." There are a few cases where an ultrasound or radiographs (X-rays) are necessary if the diagnosis is not clear based upon palpation.

For most minor hernias, it is generally safe to keep an eye on the hernia, making sure it doesn't grow until your vet can repair it surgically. Surgical repair for kittens with hernias will usually be scheduled for the time of the spay or neuter surgery, so the patient only has to undergo anesthesia and recovery a single time. As long as the cat is doing well and behaving normally at home, a hernia is not an emergency.

If the hernia is quite sizable or enlarges, it isn't safe to wait. In this case, the hernia must be addressed soon to avoid risking the abdominal cavity contents becoming trapped or twisted, compromising the cat's blood supply. This can lead to a life-threatening situation. A cat may be in critical condition because of a severe hernia, though this is uncommon.