Symptom · Dogs
Dog collapse: what it means and when to call the vet
A dog that collapses — even if they get up a few seconds later — needs to see a vet straight away. Collapse can be caused by heart problems, internal bleeding, low blood sugar, heatstroke, poisoning or seizures.
Common causes
- Heart rhythm problems or heart disease
- Internal bleeding, for example from a ruptured splenic tumour
- Seizures
- Heatstroke
- Low blood sugar
- Poisoning
- Severe allergic reaction
- Exercise-induced collapse in some breeds
What you can do at home
- Check breathing and gum colour
- Keep your dog flat and still; move with a blanket as a stretcher
- Cool with cool water if overheated
- Call the clinic on the way
What the vet may do
- Assess heart, breathing and blood pressure
- ECG and ultrasound
- Blood tests including sugar and red cell count
- Fluids, oxygen and emergency treatment
- Surgery for internal bleeding
Prevention
- Regular check-ups, especially for older and large-breed dogs
- Avoid exercise in the heat
- Keep toxins out of reach
The details
Collapse is a symptom, not a diagnosis. Fainting (syncope) is brief: the dog falls, usually stays relaxed, and recovers quickly. Seizures typically involve paddling, chomping or stiffness and a period of confusion afterwards. Filming an episode, if it is safe, helps your vet tell them apart.
In older large-breed dogs, sudden weakness with pale gums and a swollen belly can mean internal bleeding from a tumour on the spleen — a true emergency. Never assume a dog who has recovered from collapse is fine.
Questions owners ask
Is dog collapse an emergency?
Yes — treat it as an emergency and go to a vet now. Go now if you see: pale, white, grey or blue gums; swollen belly; not breathing or no heartbeat; collapse in hot weather or after exercise; repeated episodes.
What causes dog collapse?
Heart rhythm problems or heart disease; Internal bleeding, for example from a ruptured splenic tumour; Seizures; Heatstroke; Low blood sugar; Poisoning; Severe allergic reaction; Exercise-induced collapse in some breeds.
What can I do at home?
Check breathing and gum colour. Keep your dog flat and still; move with a blanket as a stretcher. Cool with cool water if overheated. Call the clinic on the way.
Sources
Tailwise is for general information and is reviewed by veterinary professionals, but it is not a substitute for advice from your own vet, who knows your pet. How we check facts