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DogCatHeart and circulation

Heart failure warning signs

Rapid or effortful breathing at rest, inability to lie down, blue-grey gums, profound weakness or collapse may signal acute worsening of heart failure. Oxygen deprivation can quickly become life-threatening.

Emergency

Go to a clinic immediately if

  • The pet struggles for breath, has blue-grey gums, cannot lie down, collapses or loses consciousness
  • Coughing frothy or pink fluid, sudden collapse or cold limbs may signal severe circulatory compromise
Contact a veterinary clinic

Possible signs

  • Rapid or effortful breathing at rest, nighttime restlessness, trouble lying down, weakness, cough or abdominal enlargement
  • A sustained rise in sleeping respiratory rate often appears before obvious respiratory distress

What it is

In heart failure, the heart cannot support circulation well enough to meet the body’s needs. Fluid may accumulate in the lungs, chest or abdomen, and tissues may receive too little oxygen. An increased sleeping or resting respiratory rate is often the first change owners notice in dogs and cats; cough alone does not prove heart failure.

What to expect at the veterinarian

If breathing is difficult, the clinic will first aim to stabilize the pet with oxygen and minimal stress. Chest radiographs or ultrasound, echocardiography, ECG, blood pressure and blood tests may follow. Depending on the cause, care may include a diuretic, drainage of chest fluid, management of heart rhythm or blood pressure and hospitalization; never change medication doses independently.

Sources

Updated: 26 Oct 2026