Unexplained Bruising in Dogs: Why Is My Dog Bleeding under the Skin? Don’t Think Minor Trauma
Trauma is not my prime suspect when I see a bruise on my dog.
The main thing to understand about bruising in dogs is that while a trauma can cause a bruise, it would need to be quite a substantial trauma. Dog skin is much thicker than human skin, and their fur provides further protection.

The only time JD had a “legitimate” bruise was when he had a close encounter with a steel rack. They disagreed about which one of them should move out of the way. The steel rack won. JD had a history of believing that if he persisted in the game of chicken, the object would move eventually.
Surgical sites end up with a lot of bruising.
If your dog ever had major surgery, such as to repair an injured knee, you would have noticed the huge amount of bruising all around it. This is further exaggerated because a large area around the incision is shaved. Otherwise, you wouldn’t see much of anything.
Why would surgery cause so much bruising since it’s not an impact blow?
A bruise is a discoloration caused by blood spilling out of damaged capillaries under the skin.
In other words, the leaked red blood cells give the bruise its appearance. You might see where I’m going with this. What if you find bruising on your dog, and there has been no trauma or surgery to explain it? What else could cause the displacement of blood from the blood vessels?
Blood is not clotting the way it should.
The body is designed to allow blood to flow where it needs to be while keeping it contained where it belongs. The two aspects involved are blood vessel permeability and blood clotting.
When the blood clotting system breaks down, blood can leak freely, even from the tiniest little “nick.” Meaning it doesn’t take actual trauma in the real sense of the word to cause bleeding. All it can take is normal wear and tear of the blood vessels. When everything functions normally, the body quickly repairs the leak. When you see unexplained bruising, you know that something went wrong with the system.
The potential causes include toxicity, auto-immune disorder, infections, and others.
The blood vessels can’t hold the blood.
Blood vessels that become too fragile, as well as an increase in blood pressure, can impair the body’s ability to keep blood from leaking out. Vascular disease can also lead to unexplained bruising.
Either way, it’s bad news.
Weird bruising on her tongue and belly was one of the symptoms Jasmine experienced after her hyperthermia horror. In addition, her platelets were devastated by the event.
The tongue, gums, eyes, and belly are the most likely places where you can notice unexplained bruising. It could look like tiny dots, specks, or large areas. It’s a sign of a serious problem. Don’t wait and see a veterinarian if you find that on your dog.
Note: Clotting problems caused by toxicity, such as rodenticide poisoning, it is more likely to see bleeding from the nose or mouth, pale gums, severe lethargy, and other signs reflecting internal bleeding.
Related articles:
Dog Skin Pigmentation Changes: Why Has My Dog’s Skin Changed Color?
Further reading:
Bleeding Under the Skin of Dogs