A hernia in cats occurs when an internal organ or tissue pushes through a weakness or opening in the surrounding muscle or connective tissue. The result is a visible lump or bulge — or in some cases, internal displacement that causes no external sign but creates dangerous organ compression. Hernias in cats range from incidental findings that require monitoring to acute emergencies demanding immediate surgery. Understanding the different types, their causes, and how they are treated helps cat owners respond appropriately when a hernia is discovered.
Types of Hernias in Cats
Umbilical hernias are the most common type in cats and occur at the navel (belly button). The umbilical ring, which normally closes after birth, fails to close completely, leaving a gap through which abdominal fat or, in severe cases, intestine can protrude. Umbilical hernias are often congenital (present at birth) and appear as a soft, reducible lump at the midline of the abdomen. They are frequently discovered during the first veterinary puppy or kitten examination.
Inguinal hernias occur in the groin area, where the inguinal canal passes through the abdominal wall. In female cats, these hernias may contain the uterus, ovaries, or intestines. Inguinal hernias can be congenital or acquired (developing later in life), and are more common in intact females, particularly pregnant or recently pregnant cats. They present as soft swellings in the groin area.
Diaphragmatic hernias occur when organs from the abdominal cavity — stomach, intestines, liver, or spleen — herniate through a tear or weakness in the diaphragm into the chest cavity. Most diaphragmatic hernias in cats are traumatic in origin (caused by car accidents, falls, or blunt force trauma), though congenital peritoneopericardial diaphragmatic hernia (PPDH) does occur. Diaphragmatic hernias cause breathing difficulty rather than a visible lump and are life-threatening emergencies.
Perineal hernias occur near the anus when the muscles of the pelvic floor weaken, allowing rectal or other pelvic contents to displace. These are far more common in intact male dogs than in cats, but do occur. They appear as soft swellings alongside the anus.
Incisional hernias develop at the site of a previous surgical incision when the abdominal wall closure breaks down. These are an uncommon complication of abdominal surgery, particularly spays or exploratory laparotomies, and typically become apparent within weeks of the original procedure.
Causes and Risk Factors
Hernias in cats arise from two broad categories: congenital defects and acquired weaknesses.
Congenital hernias — particularly umbilical and some inguinal hernias — result from incomplete closure of normal anatomical openings during fetal development or immediately after birth. There may be a genetic component in some lines, making it prudent not to breed cats with congenital hernias. Congenital peritoneopericardial diaphragmatic hernias are also present from birth and may not cause clinical signs until later in life.
Acquired hernias result from trauma, surgical complications, or increased abdominal pressure. Diaphragmatic hernias are almost always traumatic in adult cats. Inguinal hernias may develop during pregnancy as the expanding uterus increases intra-abdominal pressure. Obesity increases general hernia risk. Perineal hernias may develop as pelvic floor muscles weaken with age. Incisional hernias result from suture failure, infection, or poor healing at a surgical site.
Symptoms of a Hernia in Cats
Symptoms depend heavily on the type and severity of the hernia. External hernias (umbilical, inguinal) typically present as visible soft lumps that may change in size depending on body position. They may be reducible — meaning they can be gently pushed back through the defect with light pressure — or non-reducible (irreducible). A non-reducible hernia that is also strangulated (blood supply to the herniated tissue is compromised) is an emergency.
Warning signs that an external hernia has become strangulated include: the lump suddenly becoming hard, painful, warm, or discolored; the cat showing sudden pain, lethargy, or reluctance to move; vomiting; and loss of appetite. Any of these signs require emergency veterinary care. Strangulated hernias cause tissue necrosis (death) within hours and are life-threatening.
Diaphragmatic hernias present with respiratory signs: labored breathing, open-mouth breathing, reduced exercise tolerance, muffled heart or lung sounds on auscultation, and sometimes an asymmetrical chest. Cats with diaphragmatic hernias may prefer to sit upright to breathe and deteriorate rapidly with stress or handling. This is always an emergency.
Diagnosis and Treatment
External hernias are usually diagnosed by physical examination. Your vet will assess reducibility, size, and the contents of the hernia sac. Imaging — ultrasound or X-rays — may be used to confirm the contents and evaluate for strangulation. Diaphragmatic hernias are typically diagnosed by chest radiographs that show abdominal organs in the chest cavity.
Treatment for most hernias is surgical repair. Small umbilical hernias that are fully reducible and contain only fat — common findings in kittens — may be monitored and repaired during a scheduled spay or neuter procedure to avoid an additional anesthetic event. Non-reducible, painful, or large umbilical hernias require prompt repair. Inguinal hernias containing intestine or reproductive organs require surgical repair; inguinal hernias found in pregnant cats should be addressed promptly given the risk of uterine entrapment.
Diaphragmatic hernias require surgical repair under general anesthesia, which carries elevated risk in a compromised patient. Stabilization of the cat’s respiratory status is the first priority before anesthesia. The outcome depends on the extent of organ displacement and the duration of the hernia, but many cats recover well from diaphragmatic hernia repair if treated promptly.