Disease Guide

Diaphragmatic Hernia in Dogs and Cats: Breathing Changes, Imaging & Care [2025]

A diaphragmatic hernia occurs when abdominal organs move into the chest through a defect in the diaphragm. It may be caused by trauma or be congenital. It can affect breathing and often requires surgical repair.

Last updated: 2026/01/05
Pethealthmap Editorial Team
Sources: AVMA, ACVIM, National Taiwan University Veterinary Hospital

When to See a Vet

Seek Emergency Care Immediately

  • Persistent open-mouth breathing or extreme difficulty breathing
  • Noticeably blue or white lips or gums
  • Sudden collapse, loss of consciousness, or unresponsiveness

Schedule a Clinic Visit Soon (within 24–72 hours)

  • Significantly reduced activity with prolonged lethargy
  • Persistent loss of appetite or repeated vomiting
  • Noticeably faster breathing than usual with decreased exercise tolerance

01What symptoms suggest something is wrong?

A diaphragmatic hernia can cause abdominal organs to move into the chest, compressing the heart, lungs, and chest space. This may lead to breathing and heartbeat changes, as well as an overall drop in activity.

  • A faster heartbeat or changes in heart rhythm, often noticed as a clearly increased heart rate
  • Rapid breathing, open-mouth breathing, or reduced exercise tolerance
  • Sleepiness, low energy, or a marked drop in activity
  • Reduced appetite, vomiting, or difficulty swallowing
  • Pain, abnormal sounds, or an unusual mass may be detected when the chest or abdomen is examined

Seek emergency care immediately if you notice the following symptoms:

  • ⚠️ Difficulty breathing, open-mouth breathing, or laboured breathing
  • ⚠️ Collapse, confusion, or suddenly becoming unresponsive
  • ⚠️ Gums or lips turning blue, pale, or noticeably discoloured

02How can I assess the problem at home? Key observations and when to seek emergency care

Observing your pet at home and recording key details can help your vet assess the situation quickly and plan the right tests.

  • Record when the signs started, how long they last, and how they change
  • Measure and note the breathing rate and heart rate while your pet is resting
  • Use your phone to take videos of abnormal breathing or restricted movement to show the vet
  • Track changes in appetite, water intake, urination, and bowel movements
  • If possible, arrange an early clinic assessment where chest and abdominal X-rays can be taken

03How will the vet make a diagnosis? Common tests

Your vet will start with a physical examination and use imaging and laboratory tests to confirm whether the diaphragm is intact and whether complications are present.

Physical examination

palpation and auscultation to assess the heart, lungs, and abdomen

Chest and abdominal X-rays

to check for organ displacement and changes in the position of gas or fluid

Computed tomography (CT)

to assess the size of the diaphragmatic defect and any complications

Blood tests and biochemistry

to assess organ function and check for infection or metabolic abnormalities

Urinalysis and, when needed, assessment of heart function or anaesthetic risk

04What treatment and care are needed after diagnosis? Medication, diet changes, and home care

After treatment, ongoing monitoring of vital signs and imaging changes is important. Follow-up visits and repeat imaging are arranged as needed to confirm recovery.

  • After surgery or during conservative treatment, hospital monitoring and support for pain control and breathing may be needed
  • After returning home, keep recording changes in breathing, heart rate, and activity for comparison at follow-up visits
  • Give medications and adjust the diet as directed, and avoid strenuous activity or jumping
  • Schedule regular X-rays or CT scans to monitor organ position and recovery
  • If signs worsen or new abnormalities appear, return to your vet promptly or seek assessment at a specialist hospital

05What should I prepare before seeing the vet? Key details that help identify the cause

1
Prepare a record of symptoms, including the approximate time they began and how they have changed
2
List recent changes in diet, drinking, urination, and bowel movements
3
Prepare a list of current medications or supplements
4
Record videos of abnormal breathing or movement, and bring any previous imaging reports if available
5
Use a secure carrier and call ahead to book a clinic that can perform X-rays

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.

Frequently Asked Questions (FAQ)