The most common hematoma in dogs is an aural hematoma, a pocket of blood that forms inside the ear flap. Treatment ranges from a simple needle drainage with anti-inflammatory medication to surgery, depending on the size and how quickly you catch it. Smaller, early-stage hematomas often respond well to minimally invasive drainage, while larger or recurring ones typically need surgical repair.
What Causes Hematomas in Dogs
An aural hematoma develops when blood vessels inside the ear flap rupture, filling the space between the skin and cartilage with blood. The ear swells into a puffy, fluid-filled cushion that feels warm and spongy. Most dogs with an aural hematoma have an underlying ear infection, allergy, bite wound, or other inflammatory condition that drives them to scratch at their ears or shake their head hard enough to burst those tiny vessels.
This is an important detail, because treating the hematoma alone without addressing the root cause is a recipe for recurrence. If your dog has an ear infection or ear mites, that problem needs treatment at the same time, or the scratching and head-shaking cycle will start all over again.
Nonsurgical Treatment for Smaller Hematomas
For early-stage or smaller hematomas, most veterinarians start with medical management. This is the least invasive option and tends to produce the best cosmetic results, meaning less scarring and wrinkling of the ear flap afterward. It also costs less and usually doesn’t require sedation.
The standard approach involves draining the blood from the ear flap with a needle, then injecting an anti-inflammatory steroid directly into the space where the fluid was. Your dog will also typically take an oral steroid for 10 to 14 days, tapering down after the first week. The vet may repeat the drainage and injection weekly for one to three weeks until the hematoma resolves.
One important caveat: drainage alone, without any anti-inflammatory medication, has a poor track record. In one study, none of the 14 dogs treated with drainage alone achieved resolution. Nine of them eventually needed surgery. The steroid component appears essential for keeping the hematoma from refilling.
When Surgery Is the Better Option
Larger hematomas, or ones that keep coming back after drainage, generally require surgery. The procedure is done under anesthesia. Your vet makes an incision in the ear flap, removes the collected blood and any clots, then places sutures through the ear to hold the layers of skin and cartilage together so the space can’t refill. Some vets use small drain tubes or even buttons to keep pressure on the ear flap while it heals.
Surgery costs between roughly $535 and $1,230 nationally, based on 2025 estimates. The price varies by location, the size of your dog, and how severe the hematoma is. If you have pet insurance that covers surgery, the average out-of-pocket cost drops to around $546.
What Recovery Looks Like
After surgical repair, your dog will come home with a bandage wrapping the ear against the top of the head. This serves two purposes: it applies steady pressure to the repair site, and it prevents your dog from shaking the ear and undoing the work. Keep the bandage on for at least three days if possible. If it slips or gets tight enough to affect breathing, remove it right away, but keep in mind the ear has been folded up over the head, so cut carefully to avoid nicking the ear itself.
Check the ear daily for excessive redness, swelling, or discharge. Your dog will likely wear an e-collar (cone) to prevent scratching. Sutures typically stay in for two to three weeks while the ear flap layers bond together. Full healing can take several weeks beyond that, and some thickening of the ear flap is normal even with a good surgical outcome.
What Happens if You Don’t Treat It
A hematoma won’t resolve quickly on its own. Left untreated, the blood inside the ear flap eventually gets reabsorbed by the body, but the process takes weeks to months and comes with real consequences. As the blood breaks down, scar tissue forms between the layers of cartilage. The ear flap contracts, thickens, and crinkles into what’s commonly called “cauliflower ear.” Beyond the cosmetic issue, the deformed ear canal can trap moisture and make your dog more prone to future ear infections, creating a cycle of problems.
The hematoma itself is also uncomfortable. That swollen, heavy ear flap causes pain and irritation, and your dog will keep shaking and scratching at it, potentially making the hematoma larger.
Internal Hematomas Are a Different Situation
Not all hematomas are on the ear. Dogs can develop internal hematomas from blunt trauma (being hit by a car, for example) or from clotting disorders. These are far more serious. If blood collects inside the abdomen, a condition called hemoabdomen, your dog may show signs of weakness, pale gums, a distended belly, or collapse.
Diagnosis involves blood work and imaging, usually an abdominal ultrasound and chest X-ray, to find the source of bleeding and assess how much blood has been lost. Treatment starts with intravenous fluids and, in some cases, blood transfusions. For trauma-related internal bleeding, the veterinary team may place a tight pressure bandage around the abdomen for up to 12 hours to slow blood loss. Surgery is sometimes necessary if the bleeding doesn’t stop on its own. Dogs with clotting disorders need ongoing activity restriction to reduce injury risk.
Internal hematomas are emergencies. If your dog has been in an accident or is suddenly lethargic with a swollen abdomen, that’s a situation requiring immediate veterinary care, not a wait-and-see approach.
Preventing Recurrence
The single most important thing you can do after treating an ear hematoma is resolve whatever made your dog shake or scratch in the first place. That means finishing the full course of any ear infection treatment, managing allergies if they’re a factor, and keeping up with regular ear cleaning if your dog is prone to buildup. Dogs with floppy ears, like Basset Hounds and Cocker Spaniels, are especially susceptible because moisture gets trapped more easily in their ear canals.
If you notice your dog starting to scratch at an ear or shake their head frequently, check the ear early. Catching an infection before it escalates to aggressive head-shaking is the most reliable way to prevent a hematoma from forming in the first place.