Hemangiosarcoma
An aggressive cancer of blood vessel lining cells, most often affecting the spleen, heart, or skin.
What is Hemangiosarcoma?
Hemangiosarcoma arises from cells lining blood vessels, so it can occur almost anywhere. The most common forms are splenic, cardiac (right atrium), and cutaneous. Because these tumours form fragile blood-filled structures, they often present with sudden internal bleeding rather than a gradual decline.
Common signs and symptoms
Signs vary between dogs and can be subtle at first. Watch for the following, especially if several appear together or persist for more than a few days:
- Sudden weakness or collapse
- Pale gums
- Abdominal distension
- Exercise intolerance
- Cutaneous form: dark red or purple skin nodules
Risk factors
Certain dogs are more predisposed. Understanding risk helps you screen earlier and act sooner.
- German Shepherd, Golden Retriever, Labrador
- Large-breed senior dogs
- Sun exposure (for cutaneous form in light-skinned dogs)
When to see a vet
Use this as general triage guidance, not a substitute for veterinary advice.
- Book a routine appointment if: any dark, firm skin nodule, or a splenic mass found on wellness ultrasound.
- Seek urgent care if: collapse with pale gums — this is a life-threatening emergency.
Diagnosis and management
Diagnosis of internal tumours often happens at emergency surgery. Splenectomy plus chemotherapy is standard for splenic hemangiosarcoma. Cutaneous forms limited to the skin have a much better prognosis with surgery alone. Yunnan Baiyao is sometimes used adjunctively.