Hemangiosarcoma in Horses
Key takeaways
Hemangiosarcoma in horses is a rare yet aggressive cancer of the blood vessel walls.
- These tumors can develop anywhere in the body, but are primarily observed in the skin, eyes, muscle, spleen, lungs, and heart
- Symptoms depend on the location of the tumor but often involve respiratory distress, muscular swelling, and pale gums
- Diagnosis includes diagnostic imaging, blood work, and tumor biopsy
- Treatment primarily involves chemotherapy or palliative care, since surgical excision is not practical in most cases
- This condition has a poor prognosis and if it has metastasized throughout the body, the horse often deteriorates rapidly from onset
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A closer look: Hemangiosarcoma in Horses
Cancer is defined as abnormal, uncontrolled cell growth that usually develops into masses called tumors. Hemangiosacroma is a specific form of cancer originating from the blood vessel walls.
Although rare, hemangiosarcoma is an aggressive cancer with poor prognosis. Since the tumors originate in the blood vessels, hemangiosarcoma spreads rapidly and efficiently throughout the body and surgery to remove tumors is usually not possible due to their location.
Risk factors
Hemangiosarcomas are rare in horses. Hemangiosarcomas can rupture, causing internal bleeding. These tumors are also prone to metastasis. Internal bleeding and metastasis are usually life-threatening and can lead to rapid deterioration. Early diagnosis before rupture or metastasis occurs gives the best chance of survival.
Hemangiosarcoma does not appear to have a breed or sex-specific risk factor. This tumor generally occurs in middle-aged to older horses more frequently than younger horses or foals.
In cases of ocular and cutaneous hemangiosarcoma, there is evidence that UV exposure can increase the risk of developing hemangiosarcoma in those areas.
Hemangiosarcoma are especially prone to hemorrhaging into body cavities.
Possible causes
The causes of hemangiosarcoma are unknown.
Main symptoms
Testing and diagnosis
After a physical examination and medical history, a number of diagnostics can be done to determine the presence of hemangiosarcoma, and identify any areas of metastasis.
Additional testing includes:
- Ultrasound
- Endoscopy
- Blood work
- Tumor biopsy or cytology
Steps to Recovery
Once hemangiosarcoma is confirmed and metastases are located, there are a number of options that can be considered for treatment;
- Surgical excision: typically only skin or ocular masses can be removed in cases of hemangiosarcoma
- Chemotherapy
- Palliative care with pain management and appetite stimulants
Hemangiosarcoma has a poor prognosis. Prognosis is better in cases where the tumor can be completely removed. If the tumor has metastasized throughout the body, prognosis is very poor and horses often deteriorate rapidly. Many horses with the widespread form of disease are humanely euthanized.
Prevention
The causes of hemangiosarcoma are not known, so prevention is difficult. However, limiting UV exposure may lower the risk of development in the eyes and skin.
Hemangiosarcoma is not contagious.
Is Hemangiosarcoma in Horses common?
Hemangiosarcomas are rare in horses.
Typical Treatment
- Surgical excision
- Chemotherapy
- Palliative care
