Treatment Options for Melanoma of Gray Horses.
Abstract: All gray horses inherited a single gene mutation, STX17G, that unbalances melanocyte behavior to cause graying and propensities to develop vitiligo and melanoma. The coat color genes ASIPa and MC1RE add risk such that relative likelihood of melanoma based on pregraying coat color is black > bay > chestnut. Melanomas begin at about 4 years. Locoregional control of melanoma masses depends on surgical removal and/or intralesional chemotherapy (possibly with adjunctive hyperthermia or electroporation). Systemic treatment is not evidence based but immunomodulators (cimetidine, levamisole) and vaccines can be tried.
Copyright © 2019 Elsevier Inc. All rights reserved.
Publication Date: 2019-07-08 PubMed ID: 31279435DOI: 10.1016/j.cveq.2019.04.003Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Review
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research article delves into the various treatment options for melanoma in gray horses, tracing the condition’s likelihood back to a combination of genetic factors and outlining potential management and therapeutic strategies, including surgery, chemotherapy, the application of heat or electroporation, and the use of immunomodulators and vaccines.
Genetic Determinants of Melanoma in Gray Horses
- The research identifies a single gene mutation, STX17, as causing unbalanced melanocyte behavior in all gray horses. This imbalance results in graying and increases the propensity of the horses to develop vitiligo and melanoma.
- Further, the coat color genes ASIP and MC1R increase the risk of melanoma. The risk profile based on pre-graying coat color is highest in black horses, followed by bay and chestnut horses.
- The onset of melanomas typically begins when the horses are about 4 years old.
Treatment Options for Melanoma in Horses
- Control of melanoma masses at the locoregional level primarily involves surgical removal. Intralesional chemotherapy, possibly combined with adjunctive hyperthermia or electroporation, can also be effective.
- Systemic treatment is not yet supported by clear evidence. However, certain immunomodulators, such as cimetidine and levamisole, can be used. Another option is the trial of vaccines.
Implications of the Research
- This study elucidates the complex genetic factors contributing to the development of melanoma in gray horses. By shedding light on specific gene mutations, the research could pave the way for advancements in genetic screening and potentially preventative measures in the future.
- The range of therapeutic options outlined in the study underscores the complexity of treating melanoma in horses. The support for surgery and chemotherapy, in particular, remains consistent with many human treatment strategies.
- This study also highlights the need for more research to determine the efficacy of systemic treatments for horse melanoma, thereby identifying an area for potential future scientific investigation.
Cite This Article
APA
MacKay RJ.
(2019).
Treatment Options for Melanoma of Gray Horses.
Vet Clin North Am Equine Pract, 35(2), 311-325.
https://doi.org/10.1016/j.cveq.2019.04.003 Publication
Researcher Affiliations
- Department of Large Animal Clinical Sciences, University of Florida, PO Box 100136, Gainesville, FL 32610, USA. Electronic address: mackayr@ufl.edu.
MeSH Terms
- Animals
- Hair Color / genetics
- Horse Diseases / genetics
- Horse Diseases / therapy
- Horses
- Melanoma / genetics
- Melanoma / therapy
- Melanoma / veterinary
Citations
This article has been cited 10 times.- Muresu Ibba GM, Poeta A, De Lorenzi G, Pupillo G, D'Annunzio G, Pezzarossi A, Bisceglia I, Mangone L. Melanoma in horses: distribution by sex, age, nationality, and slaughterhouse findings in 28 horses from Northern Italy. Vet Res Commun 2025 Oct 29;50(1):12.
- Pimenta J, Cotovio M. Equine Veterinarian Perspectives on Mucocutaneous Tumors in Horses: A Survey-Based Study in Portugal. Animals (Basel) 2025 Jun 23;15(13).
- Labelle AL, Gemensky Metzler AM, McMullen RJ Jr, Wiggans KT, Labelle P, Hamor RE. Equine intraocular melanocytic neoplasia. Can Vet J 2024 Oct;65(10):1048-1054.
- Fesmire CC, Peal B, Ruff J, Moyer E, McParland TJ, Derks K, O'Neil E, Emke C, Johnson B, Ghosh S, Petrella RA, DeWitt MR, Prange T, Fogle C, Sano MB. Investigation of integrated time nanosecond pulse irreversible electroporation against spontaneous equine melanoma. Front Vet Sci 2024;11:1232650.
- Pimenta J, Prada J, Pires I, Cotovio M. Programmed Cell Death-Ligand 1 (PD-L1) Immunohistochemical Expression in Equine Melanocytic Tumors. Animals (Basel) 2023 Dec 22;14(1).
- Pimenta J, Prada J, Cotovio M. Equine Melanocytic Tumors: A Narrative Review. Animals (Basel) 2023 Jan 10;13(2).
- Yi Z, Gao Y, Yu F, Zhu Y, Liu H, Li J, Murua Escobar H. Interventions for treatment of cutaneous melanoma in horses: a structured literature review. Vet Res Commun 2023 Jun;47(2):347-360.
- Wang M, Liu M, Huang Y, Wang Z, Wang Y, He K, Bai R, Ying T, Zheng Y. Differential Gene Expression and Methylation Analysis of Melanoma in TCGA Database to Further Study the Expression Pattern of KYNU in Melanoma. J Pers Med 2022 Jul 25;12(8).
- Weber LA, Delarocque J, Feige K, Kietzmann M, Kalbitz J, Meißner J, Paschke R, Cavalleri JV. Effects of Topically Applied Betulinic Acid and NVX-207 on Melanocytic Tumors in 18 Horses. Animals (Basel) 2021 Nov 13;11(11).
- Bollard SM, Casalou C, Goh CY, Tobin DJ, Kelly P, McCann A, Potter SM. Circulating Melanoma-Derived Extracellular Vesicles: Impact on Melanoma Diagnosis, Progression Monitoring, and Treatment Response. Pharmaceuticals (Basel) 2020 Dec 18;13(12).
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists