Dog Hemangiosarcoma

Tired Golden Retriever lying on wooden floor

Hemangiosarcoma is a form of cancer that is more common in dogs than in people or other animals, and it spreads fast throughout the body. Hemangiosarcoma creates tumors in dogs, much like many other cancers do, however it can affect many different body regions. Usually, growths are seen in the skin, heart, liver, and spleen. Any breed of dog can contract this illness, although golden retrievers, German shepherds, and Labrador retrievers are the most commonly affected.

It can manifest as irregularities on the skin or more serious signs including weakness, a swollen tummy, pale gums, or even collapse. This may also be internal. It's crucial to visit a veterinarian as soon as your dog exhibits any symptoms since internal hemangiosarcoma symptoms might resemble those of other deadly illnesses. Sun exposure may be the cause of external hemangiosarcoma, however there is no recognized reason for the internal kind. Treatment should begin as soon as feasible because this illness has a catastrophic prognosis.

What is Hemangiosarcoma?

Endothelial cancer, which lines the inside of blood vessels, is known as hemangiosarcoma. It can generate tumors that are extremely malignant, develop quickly, and spread to other regions of the body (spreading to other parts of the body). The spleen, liver, heart, and skin are where hemangiosarcoma growths most frequently appear, with skin symptoms being connected to external hemangiosarcoma.

Spleen and liver tumors may bleed or burst, which might result in the abdomen filling with blood (hemoabdomen). The right atrium is where cardiac tumors most frequently develop and bleed. The pericardium, a sac around the heart, becomes filled with blood, impairing cardiac function. Heart failure can be caused by and exhibit these symptoms in hemangiosarcoma tumors that damage the heart.

Hemangiosarcoma can also manifest as skin (dermal) or subcutaneous tumors (subcutaneous). often appear as elevated pimples that are either red, purple, or black in color. They can ultimately bleed and develop ulcers. Malignant subcutaneous tumors are extremely prone to spread. When subcutaneous hemangiosarcoma first starts bleeding, it can not be apparent to the human eye and resemble a deep, spreading bruise.

Symptoms of Hemangiosarcoma in Dogs

Internal tumors (of the heart, liver, or spleen) may not initially present with any symptoms. The tumor may burst or bleed, causing the initial symptoms to be hazy before abruptly getting worse. The symptoms of internal hemangiosarcoma may resemble those of internal bleeding and cardiac problems. They may consist of:


  • Lethargy and weakness (constant or intermittent)
  • Distended abdomen (bloated appearance of belly)
  • Pale gums or mucous membranes
  • Collapse
  • Bruising, bleeding, lumpy, or ulcerated skin

Lethargy and Weakness

Like people, dogs can become sluggish when they're not feeling well, but in dogs with hemangiosarcoma, this is frequently accompanied with weakness. Affected dogs could seem particularly frail while getting out of a sitting position or after modest exercise.

Distended Abdomen

Abdominal distension looks like the dog's stomach is bloated as it fills with fluid. In dogs with hemangiosarcoma, this is caused by tumors that affect the major organs.

Pale Gums or Mucous Membranes

Pale gums can signify a wide range of medical issues, but veterinarian care is always required if your dog's gums are any color other than pink. Hemangiosarcoma in dogs is often brought on by tumor-related blood loss in the belly or the area surrounding the heart.


Collapse is another indication of severe heart disease, similar to pale gums. Due to tumors that develop inside the body close to (or on) the heart, hemangiosarcoma can manifest numerous symptoms in dogs that are similar to those of heart disease. A shortage of blood supply to the brain brought on by cardiac issues might cause your dog to lose consciousness.

Bruising, Bleeding, Lumpy, or Ulcerated Skin

Skin tumors are a sign of external hemangiosarcoma, a condition that damages the skin's blood vessels. As the condition advances, this might start as a bruise that could turn into a lumpy region, bleed, or become an ulcer. Light-colored or sparsely furred dogs may have an increased risk of developing external hemangiosarcoma because their skin is more exposed to sunlight.

Causes of Hemangiosarcoma

The etiology of the two forms of hemangiosarcoma vary. Although this illness can strike dogs of any age, it usually strikes middle-aged and elderly animals. causes might be:

  • Sun exposure: Hemangiosarcoma of the skin is typically caused by too much sun exposure. Tumors usually occur on hairless areas of the skin or areas with white hair.
  • Genetics: The cause of internal hemangiosarcomas is not fully known, and any breed of dog can get this type of cancer. However, certain breeds appear to have a genetic predisposition. These include golden retrievers, German shepherds, and Labrador retrievers.

Diagnosing Hemangiosarcoma in Dogs

If you see skin pimples, evidence of internal hemangiosarcoma, or any other symptoms of a dog sickness, take your dog to the doctor so they can thoroughly identify the problem. Your veterinarian will start by going over your dog's medical history and doing a thorough physical examination if hemangiosarcoma is suspected. During the examination, abdominal masses may or may not be palpable. Your dog's veterinarian may be able to detect blood or other fluids in the abdomen via the body. A stethoscope can detect aberrant heart sounds that may be caused by heart tumors.

Following the entire lab work (complete blood count, blood chemistry, urinalysis), radiographs (X-rays) of the chest and abdomen are the following diagnostic stages. Along with obvious tumors or anomalies in the chest and belly, your veterinarian will be on the lookout for test abnormalities that may signify cancer. Blood tests will enable your doctor to narrow down the source of your dog's disease by determining the blood cell count, blood clotting capacity, and organ function.

Skin cancers are frequently amenable to aspiration or biopsy, which entails your veterinarian collecting a sample for examination under a microscope. A pathologist examines samples to check for tiny cancer cells. If your veterinarian determines it is safe for your dog, internal tumors may also be aspirated or biopsied. Additionally, if your dog has abdominal fluid, it may be collected and submitted to a lab for testing.

In certain circumstances, the tumor must be surgically excised and referred to a pathologist in order to receive a conclusive diagnosis of hemangiosarcoma. Your regular veterinarian may recommend you for treatment to a veterinary oncologist and/or veterinarian surgeon, depending on the diagnosis.


If feasible, the main tumor should be surgically removed as the initial step in treating canine hemangiosarcoma. Usually, spleen removal in splenic tumor surgery involves the whole organ (which your dog can live healthily without). If a tumor cannot be completely removed, it may be as much as feasible debulked. Particularly heart-related cancers, some are inoperable.

Surgical removal of skin hemangiosarcomas is usually curative if the entire tumor is removed and there is no metastasis.

Both the diagnostic and therapeutic processes benefit from staging. Dogs will require comprehensive blood testing, chest and abdominal radiographs, and maybe more sophisticated imaging like CT or MRI. The veterinarian can then create the most effective treatment strategy after determining where the cancer has progressed throughout the body.

Following surgery, chemotherapy is sometimes advised for dogs, particularly if the lump could not be removed entirely or if metastases was found. The most popular chemotherapy drug is doxorubicin (Adriamycin), but a veterinary oncologist will create a program that is optimal for your dog. Every two to three weeks for several months, this normally entails trips to the veterinarian for chemotherapy injections.

Palliative radiation therapy may be recommended to reduce pain and provide a better quality of life when other treatments are not effective or if no other treatment options exist.

Prognosis for Dogs With Hemangiosarcoma

Unfortunately, internal hemangiosarcoma in dogs typically results in death. Only 10% of dogs that have surgery and chemotherapy survive for a year or more. The majority of canines usually live between five and seven months after treatment. Veterinarians can administer medications to ensure that these pets are as comfortable as possible while receiving therapy.

The type and size of the tumor that a dog with hemangiosarcoma of the skin has relies on the dog's prognosis. After completing the necessary procedures, dogs with these tumors may stay cancer-free. Not all external tumors will continue to spread after being surgically removed.

How to Prevent Hemangiosarcoma in Dogs

Since early identification is the next best approach because most kinds of hemangiosarcoma cannot be avoided, Internal variants of this illness should be avoided by selective breeding, while external hemangiosarcoma may be avoided with lifestyle management:

Early Detection

The higher a dog's prospects are for a good recovery from cancer, the earlier it is discovered. This is why it's crucial to heed your veterinarian's advice on frequent screening laboratory testing and yearly or biannual wellness checks.

Sun Exposure (External Hemangiosarcoma)

Keeping your dog out of the sun as much as possible will help avoid hemangiosarcoma of the skin. You must keep an eye on your dogs' outside time if their fur is light in color or has few hairs. It is especially important for those with thin fur to apply sunscreen before spending a lot of time outside (and some breeds with especially short or sparse fur can benefit from daily applications).

Selective Breeding

It is more challenging to stop internal hemangiosarcoma than exterior varieties. Selective breeding is an excellent strategy to help reduce the development of this illness, and dogs with a history of hemangiosarcoma should not be used for breeding. However, a lot of dogs are bred before they get hemangiosarcoma. The medical background of each litter should be disclosed by responsible breeders, with a few generations of history being the best indicator of the likelihood of cancer in puppies.


"Hemangiosarcoma in Dogs. Colorado State University Flint Animal Cancer Center.", "Visceral Vascular Tumors. VCA Animal Hospitals.", "Diagnosis of Cardiovascular Disease in Dogs. Merck Veterinary Manual.", "Vascular Tumors Affecting the Skin. VCA Animal Hospitals." ;