Aural hematomas are puffy pockets of blood

I always thought that aural hematomas (blood pockets in the ear flap) were the curse of floppy-eared dogs. Then I saw one in a German Shepherd Dog. Still, I was sure that these annoying complications were limited to dogs – until I saw one in a cat. So, what causes these big, puffy blood pockets that owners despise so much?

How hematomas form: Many people are familiar with the concept of a blood blister, like the kind you get when you pinch your finger in a door or pair of pliers (or am I the only clumsy one?). Aural hematomas are very similar to these blood blisters. They form when an ear vein is damaged and leaks blood under the skin of the ear flap. The pressure of the blood against the skin causes a pocket to form, which allows more blood to leak from the vein. This vicious cycle continues, sometimes until all available space has been used, leaving the ear very puffy and heavy. At this point, pressure or trauma may cause a small opening in the ear flap, allowing blood to ooze, pour, or otherwise escape into the environment. More typically, however, the owner is able to get the pet veterinary care while the blood is contained.

Why hematomas form: We usually find them to be secondary to external ear infections, caused by yeast, bacteria, or mites. The head shaking and scratching that often accompany ear infections cause the trauma to the ear veins that trigger the bleeding. If scratching and shaking continue after the hematoma forms, the pocket can open and drip/spray/gush blood wherever the pet is at the time. This is perhaps one of the least popular aspects of hematomas among pet owners.

Two other proposed causes of hematomas are the degeneration of cartilage within the ear flap and increased fragility of the vessels in the ear, secondary to diseases such as Cushing’s.

Treatment: There are several approaches to treating hematomas. What they have common is two major goals: drain the blood and close the pocket so that a new hematoma cannot form. Unfortunately, what vets can’t promise is that the ear flap will ever appear the way it did before the bleeding started.

The three primary treatment approaches are:

  1. Aspiration. A large-gauge needle and large syringe are used to remove the blood from the pocket. Bandaging the ear may discourage the pocket from filling again. Although this is the least invasive approach, it is also the least effective and typically not a good choice.
  2. Surgery. A vertical slit (either straight or “S” shaped) is made through the skin and into the hematoma. The blood is drained and the loose skin of the pocket is then attached to the ear flap by placing sutures or staple through both layers every inch or so. The ear looks a bit like it has been quilted – but the dead space that used to comprise the pocket is reduced so that blood has no place to collect, even though the ear will likely continue to bleed for hours after the treatment begins. Over time, the skin begins to fuse to the ear underneath and the slit starts to heal.
  3. Drain Placement. One or two holes are made to release the blood from the pocket. If two holes, a Penrose drain is laced through the holes and sutured into place. If one hole, a plastic cannula (a hollow, tapered plastic device used to treat cow udders) is sutured in place to keep the hole from closing. The goal of both techniques is to allow continued draining while the pocket closes. Sutures or staples might be placed as describe above to reduce dead space.

Any approach that removes both the blood and the dead space is generally effective. An Elizabethan collar is a key tool that prevents the animal from scratching the treatment site and slowing healing.

Prevention: It is difficult to predict which animals will develop hematomas. It is, however, possible to reduce the chances of hematoma formation by treating any and all ear infections that arise.

Aural hematomas are an annoyance. If you don’t believe me, you can ask my client who just had her dog treated for his fourth one… he’s now had two in each ear!