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Blood Blister On Dogs (Caring For Canine Skin Hematomas)

Key Takeaways

  • Blood blisters on dogs are red lumps on the skin that develop from the blood vessels, hence the medical term vascular tumors.
  • If a tumor is benign, it is called hemangioma; whereas tumors that spread on the body are called hemangiosarcomas.
  • Blood blisters can occur due to several causes including trauma, scratches, excessive head shaking, skin conditions and allergies, blood clotting, and castration surgery.

Do you spot a blood-filled sac under your dog’s skin? If you’re nodding your head “yes,” your dog may just have a blood blister. Also called vascular tumors, blood blisters are hardened red mass or lump on the skin which can grow anywhere on a dog’s body. In medical terms, vascular means anything related to blood vessels, so a blood-filled blister is called a vascular tumor which can be benign or malignant.

While a blood blister may sound really scary, it’s actually pretty common among dogs. My pets have had these red lumps one or two times. Although common, I always make sure to consult the vet every time. When a vet treats this condition, many dogs are back to normal in almost no time. Many dog owners breathe out a sigh of relief after discovering that several dogs have been healed from blood blisters. Did you just breathe out a sigh of relief too? If you’re almost sure that your dog has this condition, you probably have some questions. Here’s everything that you need to know about blood blisters in dogs. 

What Are Blood Blisters In A Dog’s Body? 

A blood blister on a dog is literally just a blood blister that can appear on basically any region of your dog’s body. Since it is a blood-filled blister, it is also known as hematoma. These blood-filled blisters are typically found on a dog’s ear flap and scrotal area, and they are rarely formed on a dog’s internal organs. Hematomas often occur when blood vessels are damaged. 

Did you know that there are two types of hematomas? The two types of hematomas in dogs: Aural and scrotal. 

Aural Blood Blisters: Typically found in a dog’s ear, aural hematomas are pretty common. Dogs with long ears are extremely prone to develop aural blood blisters. 

Aural Hematoma. | The Pampered Pup

Sacral Blood Blisters: These types of hematomas are generally present in a dog’s scrotal area, and they are more likely to develop in aging dogs with excess scrotal tissue. 

Internal Blood Blisters: As previously mentioned, internal blood blisters are extremely rare. When a dog does have an internal blood blister, it probably developed on the lungs or spleen. These types of rare hematomas can result in severe complications. 

What Causes Blood Blisters In Dogs? 

If you don’t know what causes blood blisters in dogs, you’re not alone. Many dog owners have no idea what caused their dog’s blood blister. 

Blood blisters in dogs can be caused by many different factors such as: 

Trauma: When there has been trauma to your dog’s ear, a blood blister has the potential to form. Many dogs experience trauma by fighting with other dogs. 

Scratches To The Ears: Depending on how hard your dog scratches its ears, a blood blister may potentially form. 

Excessive Head Shaking: If your dog shakes its head excessively, blood blisters are also likely to form. 

Skin Conditions And Allergies: Many dogs with conditions and allergies eventually develop blood blisters. If your dog is suffering from a skin condition that really itches, the constant scratching could result in a blood blister. 

Blood Clotting: Although it’s extremely rare, blood clotting could also cause blood blisters. 

Castration Surgery: After your dog has undergone castration surgery, blood blisters may also form. There’s a greater likelihood of blood blisters forming if your dog is extremely active right after this surgery. 

What Are The Symptoms Of A Blood Blister In Dogs? 

If your dog has a blood blister, you’ll definitely know because you can see the hematoma, and your dog will be experiencing many symptoms.  

According to many vets, the most common symptoms of a blood blister include 

  • Skin discoloration 
  • Dog ear infection
  • Debris in the ears 
  • Severe pain
  • Excessive swelling near the ear or scrotal 
  • Firmness around the affected area
  • Constant head shaking 

The symptoms of a hematoma can cause your dog pain and make him really uncomfortable and sad. If your dog is suffering from any of these common symptoms, you should get in touch with a vet sooner rather than later. Ear infections are a sure sign that your dog may have hematomas. There may also be a chance that your dog is experiencing internal symptoms like seizures in dogs, severe pain, and incontinence. While internal blood blisters aren’t common, they should be treated immediately. Many dogs with internal hematomas don’t show symptoms, but they could experience trouble breathing and coughing. Many pet owners aren’t able to tell if their dogs are suffering from internal hematomas [1].

How Does A Vet Diagnose Hematomas In Dogs?

When you take your dog to the veterinarian after noticing any of the above symptoms, the vet will be able to diagnose your dog with blood blisters. 

For a proper diagnosis, a vet will begin by asking you important questions about your dog’s history. A vet may want to know whether or not your dog is suffering from a medical condition, injury, or trauma. After going through your dog’s medical history, the vet will proceed to perform a thorough examination. In order to detect an ear infection, foreign object, or blood vessels, the vet will pay special attention to your dog’s ears. A CT scan may be necessary to figure out if your dog has an inner ear disease. 

A vet will probably test your dog’s urine and blood to determine the underlying cause of the hematoma. In other cases, skin biopsy may be necessary.

How Can You Treat Hematomas In Dogs? 

The best treatment for Hematomas in dogs will depend largely on the type and cause of the hematoma. The only way to know how a hematoma should be treated is to ask an experienced vet. 

Draining: A vet may want to drain the hematoma.

Surgery: A vet may recommend surgery if your dog is suffering from ear hematoma or internal hematomas. For the surgery, your dog will be under anesthesia. During surgery, a vet will drain the blood blister and remove the clot. Once the surgery is complete, a vet will probably bandage a dog’s ears and put an Elizabethan collar on your dog. 

A vet will also want to treat the underlying cause of the hematoma, whether it’s due to an injury, skin allergies, or another condition. By treating the underlying cause, your vet will ensure that the hematoma doesn’t reappear anytime soon.  

After treating your dog’s blood blister, you may need to take your best pal back to the vet for follow-up appointments. Make sure to let your vet if your dog experienced any problems after the treatment. 

How To Prevent Your Furry Friend From Getting A Hematoma? 

Do you want to know exactly how to keep your furry friend blood blister-free? The reality is that not all hematomas can be entirely prevented. These great tips will definitely help prevent most hematomas, though. 

Ensure that your dog maintains excellent hygiene by cleaning its ears every day

Dog chasing a ball. | The Pampered Pup
  • Get your dog neutered when it’s a puppy and monitor your dog’s activities after the procedure  
  • Protect your dog from accidents and injuries 
  • Take your dog to the vet on a regular basis. 
  • Tell your vet if your dog begins to scratch its ears excessively  
  • Break up a dog fight as soon as possible 
  • Walk your dog with a leash or let it play in a fenced yard (try any of today’s best invisible dog fences)
  • Make sure your dog doesn’t have ear infections or a skin infection 
  • Adhere to all of your vet’s great treatment recommendations if your dog is ever diagnosed with a hematoma

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The Bottom Line 

Regardless of the breed or size, almost any dog can develop a hematoma. Most blood blisters will develop near a dog’s ears.

A hematoma is usually treatable, but you shouldn’t try to treat this condition at home without talking with a vet first. 

The best way to prevent a blood blister on a dog is preventative veterinary care. Always consult with veterinary medicine experts regarding the best hematoma treatment for your dog. 


1. How do you treat a blood blister on a dog?

A blood blister on a dog can be treated in many ways. The most common treatments for blood blisters are surgery and draining. A vet will also want to treat the underlying condition. After treating the blood blister, your dog will need to wear an Elizabethan collar for a while. For the best results, you should speak to an experienced vet regarding your dog’s hematoma and blood vessels. 

2. What looks like a blood blister on a dog?

A blood blister on a dog will basically look like a blood-filled sac. The bump will probably appear pink or red, and it may even look like a big pimple.  

If you’re unsure if your dog has a blood blister, take your dog to the vet immediately. The condition will need to be treated in a timely manner. A vet will be able to tell you the cause of the blood blister as well. 

3. How can I treat a hematoma on my dog at home?

If you want to know how to treat hematomas at home, you’ll need to consult with an experienced vet. As a general rule, you should avoid draining the blood blister yourself. You also shouldn’t pop the blood blister. The best thing that you can do is give your dog an Elizabethan collar as soon as possible. After doing this, give the vet a call immediately. A vet will be able to give you some great ways to treat this condition at home. 

4. How long does a hematoma last on a dog?

If your dog receives the proper treatment, a hematoma shouldn’t last longer than several weeks. Make sure to visit a vet as soon as possible if hematoma lasts over a month. In this case, a vet may suggest another treatment for the hematoma. You can also talk with a vet to determine exactly how long the blood blister will last. The answer will probably depend on whether or not the blood blister is caused by an underlying condition. 

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2 thoughts on “Blood Blister On Dogs (Caring For Canine Skin Hematomas)”

  1. My dog has opened her hematoma and its bleeding. Is this blood draining from it? Will it heal? It’s getting smaller. I have an elizabethan collar on her and am applying betadine. Is this the right thing to do. She is 16 years old so don’t think she will cope with operation


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