A hematoma is a swelling filled with blood and caused by a rupture of blood vessels. A hematoma may occur almost anywhere on the body, but often develop on the flap of your dog's ear.

A hematoma will appear as a lump under the skin or within the ear.

A hematoma is caused by impact, and often accompanies broken bones or similar trauma. Scratching and violent head shaking can also cause a hematoma in the ear. A hematoma in the ear will develop suddenly and feel soft to the touch. Finally, a hematoma can develop from newly-closed surgical sites, especially those that are on the lower body parts of dogs such as the chest, belly and groin.

A veterinarian can usually identify a hematoma by a visual inspection. To confirm the diagnosis, your vet will analyze a small sample of fluid from the swelling. 

A hematoma can be treated in several ways depending upon its severity. For example, your vet may choose to drain the fluid from the hematoma. In most cases, however, the hematoma will go away on its own.

Treatment of conditions that may lead to ear scratching such as ear mites, bacterial infections and yeast infections, is a good way to help prevent your dog from getting a hematoma. You should also safeguard your dog from trauma.

No, you cannot contract a hematoma from your dog.