Dog symptom

Collapse / fainting in dogs

Emergency — get veterinary help right now

Collapse, fainting, sudden weakness, or inability to stand can signal shock, heart disease, low oxygen, internal bleeding, heatstroke, poisoning, or other life-threatening problems.

Common causes of collapse / fainting in dogs

  • Heart rhythm problems or fainting from poor blood flow to the brain
  • Shock from trauma, blood loss, severe infection, or allergic reaction
  • Low blood sugar, severe anemia, heatstroke, or toxin exposure
  • Breathing problems or low oxygen

Who's most at risk

  • Pets with heart disease or a murmur
  • Senior and large/giant breeds
  • Brachycephalic breeds (heat and airway)
  • Pets with anemia or a bleeding risk

What you can do at home

  • Keep your pet quiet, warm, and on their side if they cannot stand
  • Check breathing and gum color if you can do so safely
  • Do not give food, water, or medicine if your pet is weak, unconscious, or disoriented
  • Go to an emergency clinic immediately

When to see a vet

  • Any collapse, fainting, or inability to stand
  • Pale, white, blue, grey, or very red gums
  • Trouble breathing, severe weakness, bleeding, vomiting, or a painful/swollen belly
  • Collapse after heat exposure, exercise, trauma, or possible toxin exposure

When it's more serious

  • Get to an emergency clinic immediately and keep the airway clear.
  • Off-color gums signal shock, bleeding, or low oxygen — emergency now.
  • Recurrent collapse (often heart-related) needs a prompt veterinary work-up.

What your vet may do

  • Check heart rhythm, gum color, and blood pressure
  • ECG, chest X-rays, and a heart ultrasound
  • Bloodwork for anemia, blood sugar, and organ issues
  • Treat the cause; stabilize and monitor

Questions to ask your vet

  • Is this the heart, the lungs, or something else?
  • Does my pet need an ECG or heart scan?
  • Could it happen again, and is it dangerous?
  • What activity is safe meanwhile?

Frequently asked questions

What causes collapse / fainting in dogs?

Collapse, fainting, sudden weakness, or inability to stand can signal shock, heart disease, low oxygen, internal bleeding, heatstroke, poisoning, or other life-threatening problems. Common causes include: Heart rhythm problems or fainting from poor blood flow to the brain; Shock from trauma, blood loss, severe infection, or allergic reaction; Low blood sugar, severe anemia, heatstroke, or toxin exposure; Breathing problems or low oxygen.

Is collapse / fainting in dogs an emergency?

Emergency — get veterinary help right now. See a vet right away if: Any collapse, fainting, or inability to stand; Pale, white, blue, grey, or very red gums; Trouble breathing, severe weakness, bleeding, vomiting, or a painful/swollen belly; Collapse after heat exposure, exercise, trauma, or possible toxin exposure.

What can I do at home for a dog with collapse / fainting?

Keep your pet quiet, warm, and on their side if they cannot stand Check breathing and gum color if you can do so safely Do not give food, water, or medicine if your pet is weak, unconscious, or disoriented Go to an emergency clinic immediately

Sources

Reviewed by the Webvet Veterinarian Team

This guide is general information, not a diagnosis, and does not replace an exam by your veterinarian. If your pet is in distress, contact your vet or an emergency clinic right away.

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