When Things Give Way …

December 26, 2025

Hernias in Cats

Nancy Kerr

Whenever you handle your cat, it is a good idea to take note of any unusual lumps and bumps that you notice since this may be a sign of a medical condition such as a hernia that requires treatment.

“A hernia is the protrusion of a portion of an organ or tissue through an abnormal opening. These abnormal openings often occur in areas where the body wall does not close properly at birth (such as the umbilicus or “belly button”). Common congenital hernias involve an abnormal opening in the wall of the abdomen or the diaphragm (the sheet of muscle that separates the chest from the abdomen). The defect may allow abdominal organs to pass into the chest or bulge beneath the skin.”¹

Hernias can be congenital (present at birth) or the result of an accident or trauma. While hernias are not common in cats, they can be serious if left untreated. Untreated hernias can worsen over time, and depending on the type of hernia, “in rare cases, a portion of the intestines or other tissues can get trapped and become strangulated (blood flow is cut off to the tissue, causing its death).”²

Types of Hernias

The most common types of hernias that occur in cats and kittens are categorized by the area of the body in which they appear: umbilical, inguinal and hiatal. An umbilical hernia is “a protrusion (outward bulging) of the abdominal lining, abdominal fat, or a portion of abdominal organ(s) through the area around the umbilicus (also called the navel or belly button). Umbilical hernias are usually painless. The exact incidence and cause are unknown. Certain family lines have a higher incidence of umbilical hernias, suggesting at least a partial genetic predisposition to the condition.”² Inguinal hernias occur in the groin area “mostly in females, occasional inguinoscrotal hernia in the males. Usually acquired in middle-age, particularly after pregnancy [these] may also occur after trauma causing abdominal compression.”² “Hiatal hernias involve extension of part of the stomach through the diaphragm. These hernias may be “sliding” and result in signs (such as loss of appetite, drooling, or vomiting) that come and go.”¹ A less common type of hernia is the diaphragmatic hernia. “The diaphragm is the muscular partition that separates the abdomen and the chest. Tearing or disruption of this thin muscle is called a diaphragmatic hernia or diaphragmatic rupture.”³ It is frequently associated with blunt trauma such as a fall or being hit by a car. The cat may develop respiratory distress, and a leaner individual may have a wasp-like body shape from abdominal organs shifting forward into thoracic space.

Symptoms

Hernias are often caused by a traumatic injury or a congenital condition, meaning the cat is genetically predisposed to developing them. They can also occur due to a weak muscle wall or for other reasons such as “defects in tissue development, pregnancy, obesity and underlying metabolic disorders. Untreated constipation can result in a hernia caused by straining. While hernia symptoms will vary depending on the type and severity, the common “characteristic symptom is a compressible bulge under the skin.”⁴ If the cat is experiencing “vomiting, fever, lack of appetite, pain, and changes in stool,”⁴ get it to the veterinarian ASAP. “In some cases, the hernia occurs inside the body and is not detectable without diagnostic imaging. Most internal hernias are found when investigating other conditions because they cause no symptoms unless they become strangulated.”⁴

Complications

“In cases where the tissue protruding through the hernia becomes strangulated, symptoms become severe. Symptoms include pain, vomiting, fever, constipation and straining to defecate, diarrhea, loss of appetite, blood in urine and behavior changes. In cases of strangulated hernia, emergency veterinary attention is required. In the case of diaphragmatic hernia, depending on the size of the hernia, the abdominal organs can protrude through the hole and take up space in the chest cavity. In these cases, the lungs and heart become crowded. Symptoms of diaphragmatic hernias are more severe and require emergency veterinary care. They include coughing, lethargy, lack of appetite, difficulty breathing, rapid breathing, fever and collapse.”⁴

Diagnosis

If you think your cat has a hernia, it is important to get it to a veterinarian quickly before the symptoms worsen or the hernia becomes strangulated. Your vet will ask you about your cat’s symptoms, review your cat’s medical history, and do an end-to-end physical exam. This will involve checking for any lumps or bumps that might indicate a hernia. Bloodwork may also be performed to assess overall health and rule out any underlying illnesses. X-rays or ultrasound may be required to confirm the hernia diagnosis and help determine the best course of treatment.

Treatment

Sometimes protruding internal organs may simply be pushed back through the muscle wall, which in turn may allow the hole to close up and heal once the organs are back in the abdominal cavity. However, there is a good chance the hernia will recur, so most veterinarians will recommend surgical repair of the muscle wall, since a small opening could potentially lead to another hernia and risk of intestinal strangulation.

Since hernias most commonly appear in kittens or adolescent cats, veterinarians will often correct the problem when the cat is neutered or spayed. After that procedure is performed, the hernia is repaired. This way, the cat only needs anesthesia and post-op recovery once rather than twice, but seriatim operations do extend the surgery time.

Prognosis

The good news is that when treated early, hernia repairs in cats tend to have very few complications and are unlikely to recur. The overall outlook is generally very good after corrective surgery.

However, “the prognosis for any patient with diaphragmatic hernia is always initially guarded. It improves if the patient has been stabilized and the heart rhythm is normal. After surgery, the risk of a condition called re-expansion pulmonary edema may occur, in which fluid can fill the lungs. Therefore, a guarded prognosis must be given for at least 24 hours after any surgery. The prognosis for a young kitten with a congenital diaphragmatic hernia is guarded to good, depending on the specific diaphragmatic defect and the abnormalities found during surgical correction.”³

Most cats do very well after surgery and go on to live full and normal lives. Note: it is possible for a female cat who has had a C-section to develop a hernia along that incision line. If you have a cat with a hernia, whether the result of a C-section or trauma, breeding is not recommended. Likewise with congenital hernias, because the tendency to develop hernias may be inherited.

Prevention

There are some things you can do to help prevent certain types of hernias in your cat. Keep your cat inside: outdoor cats are at a greater risk for hernias caused by accidents or trauma. Secure windows and screens to prevent the cat from falling from a window. Protect your cat on outdoor balconies by securing the spaces between railings, etc. Cat-proofing your home will help to avoid falls from very high areas and prevent your cat from accidentally knocking something heavy down upon itself. Lastly, but very important: regular veterinary visits will help to detect a hernia before it becomes a major issue.

Sources

1. Lisa K. Pearson, DVM, MS, PhD, DACT, Washington State University, Congenital and Inherited Disorders of the Digestive System in Cats, Sept 2024, Accessed 10/19/2025, https://www.merckvetmanual.com/cat-owners/digestive-disorders-of-cats/congenital-and-inherited-disorders-of-the-digestive-system-in-cats#Hernias_v3243579
2. Malcolm Weir, DVM, MSc, MPH; Tammy Hunter, DVM; Ernest Ward, DVM, Umbilical Hernia in Cats, Accessed 10/19/2023, https://vcahospitals.com/know-your-pet/hernia-umbilical-in-cats
3. Courtney Barnes, BSc, DVM; Tammy Hunter, DVM; Ernest Ward, DVM, Diaphragmatic Hernia in Cats, Accessed 10/19/2025, https://vcahospitals.com/know-your-pet/hernia-diaphragmatic-in-cats
4. Hernias in Cats, Accessed 10/19/2025, https://vetster.com/en/conditions/cat/hernias