Impact of Excision Interval on Equine Melanoma Progression

The Impact of Excision Interval on Equine Melanoma Progression: Time Matters?

Animals (Basel). 2024 Apr 22;14(8):1244. doi: 10.3390/ani14081244.
Authors
José Pimenta 1 2 3 , Justina Prada 1 2 4 , Isabel Pires 1 2 4 , Mário Cotovio 1 2 4 5
Affiliations

1 CECAV-Veterinary and Animal Research Center, University of Trás-os-Montes e Alto Douro, 5000-801 Vila Real, Portugal.
2 Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 5000-801 Vila Real, Portugal.
3 CIVG-Vasco da Gama Research Center, EUVG-Vasco da Gama University School, 3020-210 Coimbra, Portugal.
4 Veterinary Sciences Department, University of Trás-os-Montes e Alto Douro, 5000-801 Vila Real, Portugal.
5 Faculty of Veterinary Medicine, Lusófona University, Campo Grande 376, 1749-024 Lisbon, Portugal.

PMID: 38672392
DOI: 10.3390/ani14081244

Abstract

Equine melanomas are a common neoplasm in gray horses. However, scientific knowledge about their progression over time is quite scarce. Some owners and veterinarians still believe that early intervention is not necessary, stating that tumors evolve very slowly and intervention could worsen the animal’s condition. This work aims to identify clinical and histological differences that may exist between equine melanomas with different excision intervals (time between tumor detection and surgical excision). A total of 42 tumors (13 benign and 29 malignant) from 34 horses were included in this study. There was a statistically significant association between excision interval and tumor size (p = 0.038), with tumors excised later being significantly larger than the ones excised sooner. The excision interval was also statistically associated with the number of tumors (p = 0.011), since the horses that carried a tumor for longer seemed to be prone to have multiple tumors. Furthermore, there was an association between excision interval and malignancy (p = 0.035), with tumor excised later being fives times more likely to be malignant. This study provides evidence of delayed excision’s effect on the progression of equine melanomas. Additionally, it reinforces the importance of the early excision of these tumors.

Keywords: clinical factors; equine; histology; melanomas; time.