Irish veterinary journal2013; 66(1); 22; doi: 10.1186/2046-0481-66-22

Malignant melanoma in a grey horse: case presentation and review of equine melanoma treatment options.

Abstract: A 15 year-old grey Thoroughbred gelding presented for investigation of chronic weight loss and recent onset of respiratory difficulty. Clinical examination confirmed tachypnoea with increased respiratory effort. Thoracic ultrasound examination detected pleural effusion. The dyspnoea was related to the large volume of pleural effusion and, following post-mortem examination, to the presence of a large mediastinal mass. Multiple pigmented masses, likely melanomas, were detected peri-anally. Thoracic radiography, cytological examination of the pleural fluid and a fine needle aspirate of a thoracic mass led to a presumptive diagnosis of malignant melanoma and this was confirmed at post mortem examination. Further metastatic spread to the central nervous system and right guttural pouch was also identified. In conclusion this case manifests the potential malignant behaviour of equine melanomas, and a review of proposed therapies for melanoma treatment highlights the therapeutic options and current areas of research.
Publication Date: 2013-11-06 PubMed ID: 24196087PubMed Central: PMC4226278DOI: 10.1186/2046-0481-66-22Google Scholar: Lookup
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This research focuses on a case of malignant melanoma in a 15 year old horse, which led to chronic weight loss and respiratory difficulties. The article investigates the clinical signs, diagnosis procedures, and provides a review of potential treatment options based on current research on equine melanomas.

Clinical Presentation

  • In this case study, a 15-year-old grey Thoroughbred gelding was presented with chronic weight loss and recent onset of respiratory difficulties.
  • On clinical examination, tachypnoea (rapid breathing) and increased respiratory effort were identified, suggesting issues with the respiratory system.
  • Thoracic ultrasound examination detected pleural effusion, which is the build-up of excess fluid between the thin layers of tissue (pleura) lining the outside of the lungs and the inside of the chest wall.
  • Multiple pigmented masses, suspected to be melanomas, were detected in the peri-anal region of the horse.

Diagnostic Procedures

  • Thoracic radiography, cytological examination of the pleural fluid, and a fine needle aspirate of a thoracic mass were conducted for diagnostic purposes.
  • The combined results of these tests led to a presumptive diagnosis of malignant melanoma.
  • The presence of a large mediastinal mass and the pleural effusion were thought to be the cause of the horse’s respiratory difficulties.
  • Post-mortem examination confirmed the diagnosis of malignant melanoma and identified further metastatic spread to the central nervous system and the right guttural pouch, an air-filled pouch located in the horse’s throat setting a precedent that even equine melanoma can metastasize to other body parts.

Treatment Options and Research

  • The case highlighted the potential malignant behaviour of equine melanomas.
  • The article conducted a review of potential therapies for melanoma treatment, showcasing the variety of therapeutic options available and highlighting the current areas of research in this field.
  • While no specific treatments were outlined in the abstract, the focus on current research underscores the importance of scientific exploration in developing effective treatments for malignant equine melanomas.

Cite This Article

Metcalfe LV, O'Brien PJ, Papakonstantinou S, Cahalan SD, McAllister H, Duggan VE. (2013). Malignant melanoma in a grey horse: case presentation and review of equine melanoma treatment options. Ir Vet J, 66(1), 22.


ISSN: 0368-0762
NlmUniqueID: 0100762
Country: Ireland
Language: English
Volume: 66
Issue: 1
Pages: 22

Researcher Affiliations

Metcalfe, Lucy Va
  • Section of Veterinary Clinical Studies, School of Veterinary Medicine, Veterinary Science Centre, Belfield, Dublin 4, Ireland.
O'Brien, Peter J
    Papakonstantinou, Stratos
      Cahalan, Stephen D
        McAllister, Hester
          Duggan, Vivienne E


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