Disseminated Hemangiosarcoma in a Mare Mule

Area of Science:

• Veterinary Medicine
• Oncology
• Comparative Pathology

Background:

• Hemangiosarcoma is an aggressive vascular tumor commonly diagnosed in dogs but rarely reported in equids.
• This case highlights the importance of considering rare differentials in veterinary oncology.

Observation:

• An 8-year-old mare mule presented with a facial mass, anorexia, unilateral epistaxis, and purulent nasal discharge.
• Diagnostic imaging revealed extensive local infiltration and suspected metastatic disease.
• Necropsy confirmed disseminated tumoral lesions consistent with hemangiosarcoma.

Findings:

• Microscopic examination confirmed hemangiosarcoma as the definitive diagnosis.
• Metastasis was observed in multiple organs including the lungs, spleen, adrenal glands, ovary, oral cavity, and frontal sinus.
• The tumor's extensive local invasion and widespread metastasis contributed to the poor prognosis.

Implications:

• Hemangiosarcoma should be considered in the differential diagnosis for equids presenting with similar clinical signs and imaging findings.
• Early recognition and diagnosis are critical for appropriate case management, even in rare presentations.
• This case adds valuable data to the understanding of hemangiosarcoma occurrence and behavior in equids.