Internal Bleeding in Dogs: The Emergency You Cannot See

The bleeding that kills dogs is usually the bleeding you cannot see. You have to read the dog rather than look for blood.

A dog is clipped by a car, picks itself up, and walks away. No wound worth mentioning, no blood on the road. Everybody is enormously relieved.

An hour later it is quiet, its gums are pale and its paws are cold.

Internal bleeding is the dangerous one precisely because there is nothing to see. A dog can lose a third of its blood volume into its own abdomen or chest without a drop reaching the floor, and the first evidence is a change in the dog rather than a mess on the carpet.

How to recognise it

You are reading the dog, not looking for blood. Suspect it after any fall, road accident or fight, and after any possible access to rat poison.

• Pale, white or grey gums. Healthy gums are salmon pink, and it is worth knowing what your own dog's normally look like
• Cold ears, paws and tail, a body that feels cool
• Weakness, wobbliness or collapse
• A hard, swollen or distended belly
• Bruising under the skin or on the gums
• Bleeding from the nose, mouth or back end, coughing up blood, or blood in the urine
• Fast, shallow or laboured breathing
• A weak, racing pulse that is difficult to find

Pale gums in a dog that has had any kind of impact is enough on its own. Do not wait for a second sign.

What to do

1. Ring the vet immediately and say what happened, so they can prepare blood products, a drip and an ultrasound to find the source.
2. Keep the dog warm and still. Stillness genuinely slows the rate of bleeding, and warmth fights the shock that comes with blood loss.
3. Carry rather than let it walk, even if it seems able to.
4. Go. There is no home treatment for this at all.
5. Watch the breathing on the way. If it becomes irregular or stops, start CPR while somebody else drives.

What not to do

Do not press on the belly to check. People do this to feel whether something is wrong, and the abdominal wall is one of the things holding pooled blood in place. Pressing can dislodge clots and accelerate the bleed.

Do not give food or water. Surgery is a real possibility and it needs an empty stomach.

Do not give aspirin, ibuprofen or paracetamol. Beyond being toxic to dogs, the first two thin the blood and will make any bleed worse.

Do not be reassured by the absence of a wound. That is the entire problem here.

Two causes worth knowing about

Rat poison. The anticoagulant baits stop blood clotting, and the bleeding they cause can begin days after the dog ate anything. So bruising, pale gums or unexplained weakness in a dog with any possible access to bait is an emergency, even if the exposure was last week and nothing happened at the time.

A ruptured splenic mass. In older dogs, a tumour on the spleen can bleed suddenly and heavily with no injury involved at all. The picture is an older dog that collapses out of nowhere, with pale gums and often a swollen abdomen, sometimes rallying briefly before going down again. It is one of the commonest true emergencies in older large-breed dogs, and it needs surgery, fast.

If your dog is elderly and collapses without explanation, do not talk yourself into it being a funny turn. Check the gums and go.

The one thing to check at home

Learn what your own dog's gums look like when it is well. Lift the lip now, while nothing is wrong, and have a proper look at the colour.

It sounds trivial and it is the single most useful observation an owner can make in an emergency, because pale gums only mean something if you know what normal looked like. Dogs vary, and some have pigmented gums where you need to check the inner eyelid or the tongue instead.

Sources

This article was written using guidance from PDSA, the UK's largest veterinary charity, whose Pet Health Hub is written by its own vets and nurses; AVMA, the American Veterinary Medical Association, the professional body representing US veterinarians; and RSPCA, the Royal Society for the Prevention of Cruelty to Animals, the UK's oldest animal welfare charity. This guidance is for general information and does not replace a consultation with your own veterinarian. In an emergency, always contact a vet. Read [how we write our health guidance](https://rochsociety.com/how-we-write-our-health-guidance/). Last reviewed July 2026.