What is a hernia?

What causes a hernia?

What types of hernias are there?

What problems do hernias cause?

What are the signs of hernias?

How is a hernia diagnosed?

Does my pet need surgery?

How is a hernia repaired?

What if I don't do surgery?

What is the aftercare with surgery?

Will my pet have a normal life? What is the prognosis?

Definition: A hernia is the protrusion of an organ or tissue through a defect in the wall of an anatomical cavity in which it normally lies


Anatomical location

  • Abdominal
    • Femoral - rare; herniation along the length of the femoral artery and vein as they exit the abdominal cavity
    • Inguinal - in the groin; the region where the back leg joins the abdomen
    • Scrotal
    • Traumatic/incisional (see below)
    • Umbilical - at the site of the umbilical cord attachment
    •  other ventral mid-line hernias
  • Diaphragmatic
    • Diaphragmatic - herniation of abdominal contents into the chest/thorax via a defect in the diaphragm itself
    • Hiatal - hernation through/around the pre-existing hole between the chest and abdomen through which the esophagus passes before continuing into the stomach
    • Peritoneo-pericardial (through the diaphragm and extending into the pericardial sac, the sac around the heart)
  • Perineal - breakdown of the pelvic diaphragm supporting the rectal wall
    • Abdominal contents protrude into a swelling lateral to the anus
  • Other - brain, etc., will potentially discussed under the respective tissue

Congenital vs. Acquired

  • Congenital - due to defect present at birth
    • herniation may be present at birth
      • signs may not develop until later
    • herniation may not develop until later
    • Common types
      • Diaphragmatic
        • Congenital diaphragmatic hernias are often small and prone to acute decompensation with tissue strangulation/necrosis and life-threatening complications
      • Inguinal
      • Umbilical
    • Some but not all such hernias are heritable defects
      • Talk to your vet about spaying/castrating your pet to prevent passing the problem on to offspring
  • Acquired - defect occurs later in life
    • Trauma
      • "False" hernias - lack the tissue sac surrounding the hernia contents
      • Blunt trauma
        • Hit by car or other vehicle
        • Running into a stationary object (wall, tree, etc.)
        • Falling down stairs
        • Fight with human or another animal
        • Common types
          • Flank - lateral abdominal wall
          • Diaphragm
            • Often a larger hernia
      • Surgical trauma
        • Wound/incision fails to heal and breaks down
    • Degeneration - breakdown occurs due to tissue weakening
      • Steroids
      • Other hormones or medications

Severity (in terms of risk to tissue)

  • Reducible
    • Protruding hernial contents are freely movable
    • Contents able to be manipulated back into original location
  • Incarcerated
    • Adhesions/scar tissue prevents the contents from being reduced to original location
    • Intestine, bladder or other organs may or may not be obstructed, which can cause more severe or even life-threatening signs
  • Strangulated
    • Vascular (blood) supply to the herniated tissue is obstructed
    • Swiftly results in necrosis (death) of herniated contents
    • Rapidly life-threatening complications
  • Space-occupying
    • Hernia contents compress and impede the function of the normally present tissues
      • Diaphragmatic hernias can compress the lungs
      • Peritoneo-pericardial hernias impair both heart and lung function

Contents - hernias can also be described in terms of the hernia's contents

  • Bladder
  • Intestine
  • Omentum

Signs of herniation

  • Swelling
    • Reducible or not
  • Pain on palpation (feeling/manipulation) of the swollen region if:
    • Inflammation
    • Infection
    • Strangulation
  • Vomiting if:
    • Bowel obstruction/strangulation
    • Toxemia from urine obstruction
    • Pain
  • Specific signs dependent on tissues involved


  • Palpation (physical examination by a veterinarian)
  • Radiographs (x-rays)
  • Ultrasound may rule out other causes of swelling
  • Computed Tomography
  • Magnetic Resonance Imaging


  • Surgery is the standard of care to repair a hernia.
  • Some very small hernial defects without incarcerated contents -- such as a 1-2 mm umbilical hernia that only contains a little bit of fat -- may not cause a problem; may recommend correction only if already undergoing surgery +/- entering the abdomen
  • Rarely, some extremely large hernias can be very difficult to repair and don't cause problems because the tissue is not compromised/constricted.
  • Still, in the vast majority of cases, an experienced, board-certified surgeon can accomplish a repair, improve your pet's quality of life, and eliminate the potential for future life-threatening complications.
  • Without surgery, you run the risk of acute development of potentially life-threatening problems.

Hernia repair

  • Open the original/appropriate body cavity and/or hernial sac
  • Return contents to original cavity
    • Enlarge (temporarily) hernia neck if necessary
    • Breakdown adhesions as needed
  • Securely/permanently close the hernia neck to prevent recurrence
    • Minimize tension
  • Obliterate (close or remove) any redundant hernial sac tissue
  • Close with patient's own tissue if possible
    • If insufficient primary tissue, consider:
      • Flap/translocation of other tissue
      • Synthetic mesh
  • Remove devitalized/non-viable tissue

Post-operative care

  • Intensive/critical care as needed
  • Antibiotics if needed
  • Pain medication
  • Minimize trauma/prevent breakdown; prevent:
    • Barking
    • Vomiting
    • Running/jumping/play
    • Sedation if needed


  • Many pets go on to a full recovery without long-term complications
  • Generally corresponds:
    • Health of the patient at the time of surgery; negatively affected by:
      • Hypovolemic shock (collapse of blood pressure, etc.)
      • Infection
      • Other disease
    • Health of the herniated tissue
      • Necrotic/dead tissue releases toxins that cause life-threatening problems
    • Health of the normally present tissue compressed by the hernia
      • Heart and/or lung damage can cause life-threatening problems
    • Risk of recurrence

What if you do nothing?

  • It is a common misconception that if something hasn't caused a problem yet, that it never will. 
  • The first part of the sentence is hasn't caused a problem YET.
  • Many pets with hernias are at significant risk for sudden, life-threatening problems, while the risk is much smaller if surgery is performed when your pet is stable. 

Please schedule an appointment with our board-certified surgeon, Dr. Jeff Christiansen at the clinic of your choice, to discuss hernias and surgery to improve your pet or patient's length and quality of life.

If you have additional questions, please feel free to e-mail Dr. Christiansen directly.


Superior Veterinary Surgical Solutions

Animal Specialty and Emergency Hospital - (321) 752-7600

Please ask for Dr. Christiansen specifically to make sure you see me!


Read What Our Clients Say

  • "My Labradoodle, LuLu, needed knee surgery. Her health is my top priority, so I researched Veterinary Surgeons, and Dr. Christiansen was highly recommended to me. My experience with him has been wonderful, and Lulu loves him. His demeanor with her was so compassionate, you could really see how much he cares about animals.

    Lulu is fully recovered from her surgery, yet I still look to Dr. Christiansen as a source of advice and expertise regarding Lulu's well being."
    Debbie Arluck - Palm Bay, Florida