Abstract: Skin wounds are common in horses due to species-specific behavioral responses. Equine skin morphology, vascularization, and inflammatory responses to wounds are comparable to those in humans, supporting the translational relevance of equine wound-healing studies. Investigating biomaterials such as tilapia and frog skin may improve wound management. This study demonstrated that sterilized tilapia and frog skin exhibit promising wound-healing properties. Unassigned: Macroscopic, microscopic, and thermographic aspects of second-intention wound healing were compared in six horses with surgically induced skin wounds treated topically with frozen tilapia skin (FTS), sterilized tilapia skin (STS), sterilized frog skin (SFS), or lactated Ringer's solution (CW). Wounds were created bilaterally in the thoracolumbar region, with one side designated for histopathological evaluation and the contralateral side for macroscopic assessment, including photographic documentation, wound area measurement, contraction rate, and thermographic analysis. Treatments were applied daily, and wound progression was monitored for 28 days. Evaluations were performed on days 0, 3, 7, 14, 21, and 28 after wound induction. Unassigned: No clinical abnormalities were observed in the horses throughout the study. Regarding wound area, the FTS group exhibited the largest lesions on day 14 compared with the CW group. Over time, the CW and FTS groups showed reduced wound contraction, with increased wound area on day 7. Histopathological evaluation revealed a significant increase in polymorphonuclear cells (PMNs) in all groups on day 3, which persisted until day 7 in the CW group and until day 28 in the FTS group. Thermographic analysis showed no significant differences among treatments. Unassigned: Sterilized tilapia skin reduced the inflammatory response, enhanced wound-edge contraction, and accelerated healing. Frog skin was associated with faster reduction of edema and hemorrhage, as well as more pronounced fibroplasia during the early stages of healing. In contrast, frozen tilapia skin showed limitations, including lower adherence to the wound bed, increased contamination, and delayed healing.
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Overview
This study evaluated the effectiveness of different types of fish and amphibian skin dressings—frozen tilapia skin, sterilized tilapia skin, and sterilized frog skin—in promoting healing in horse skin wounds compared to a standard treatment.
It demonstrated that sterilized tilapia and frog skin dressings have beneficial effects on wound healing, unlike frozen tilapia skin, which showed several drawbacks.
Background and Rationale
Equine skin wounds are frequent due to typical horse behaviors causing trauma.
Healing processes in horse skin share similarities with human skin—including anatomy, blood supply, and inflammatory responses—making horses useful models for studying wound healing relevant to humans.
Wound dressings derived from natural biomaterials like fish and frog skin are of interest because they may enhance healing due to their biological properties.
This study focused on comparing three dressings:
Frozen tilapia skin (FTS)
Sterilized tilapia skin (STS, treated with gamma radiation)
Sterilized frog skin (SFS)
Control treatment with lactated Ringer’s solution (CW)
Study Design and Methodology
Six horses were used, creating bilateral, surgically induced skin wounds in the thoracolumbar region (middle back).
Each horse’s wounds were split, with one side used for histopathology (microscopic tissue analysis) and the other for macroscopic (visual) and thermographic analysis.
Treatments were applied topically and refreshed daily over 28 days.
Evaluations occurred on days 0, 3, 7, 14, 21, and 28, using:
Macroscopic measurements: photographic documentation, wound area size, and contraction rate.
Histopathology: assessing inflammatory cells and tissue repair progress.
Thermography: measuring temperature changes to infer inflammation or infection.
No adverse clinical signs were noted in any horse throughout the study.
Main Findings
Wound Size and Contraction:
The frozen tilapia skin (FTS) group had larger lesions by day 14 compared to the control group, indicating slower healing.
Both FTS and control groups showed reduced wound contraction (shrinkage) with an increase in wound size at day 7, suggesting delayed healing during that period.
Inflammatory Response:
Polymorphonuclear cells (PMNs), a type of immune cell active in early inflammation, increased significantly in all groups by day 3.
PMNs remained elevated until day 7 in the control group, but persisted until day 28 in the frozen tilapia group, indicating prolonged inflammation.
Sterilized tilapia skin reduced this inflammatory response compared to frozen skin.
Thermographic Analysis:
No significant differences in wound temperature were observed between the different treatment groups across time points.
This suggests that thermal imaging detected similar levels of inflammation or infection across all dressings.
Histopathology Findings:
Sterilized tilapia skin (STS) enhanced wound-edge contraction and accelerated healing by reducing inflammation.
Sterilized frog skin (SFS) helped reduce edema (swelling) and hemorrhage (bleeding) faster, and promoted greater fibroplasia (formation of fibrous tissue) early in healing.
Frozen tilapia skin had poorer wound bed adherence, was more prone to contamination, and delayed the healing process.
Implications and Conclusions
Sterilization of fish skin (via gamma radiation) significantly improves its suitability as a wound dressing by reducing contamination risk and inflammatory complications.
Biological dressings like sterilized tilapia and frog skin support various aspects of healing, making them promising alternatives or adjuncts to standard wound care in veterinary settings, with potential translational value for human wound management.
Frozen tilapia skin, if not properly sterilized or prepared, may hinder healing due to its limitations in wound adherence and contamination susceptibility.
Future work could further optimize sterilization methods and explore scaling these dressings for clinical use in both animals and humans.
Cite This Article
APA
Miranda RPDR, de Miranda BA, Aranha AB, Gomes Ramos MFB, Oliveira EP, Dallago BSL, Adorno J, Macêdo IL, Castro MB, Campebell RC.
(2026).
Evaluation of tilapia skin (Oreochromis niloticus) frozen, frog skin (Rana catesbeiana), and tilapia skin (Oreochromis niloticus) sterilized with gamma rays dressings, in equine skin wound healing.
Front Pharmacol, 17, 1896365.
https://doi.org/10.3389/fphar.2026.1896365
Hospital Escola de Grandes Animais, Faculdade de Agronomia e Medicina Veterinária (FAV), Universidade de Brasília (UnB), Brasília, Brazil.
de Miranda, Beatriz Alves
Hospital Escola de Grandes Animais, Faculdade de Agronomia e Medicina Veterinária (FAV), Universidade de Brasília (UnB), Brasília, Brazil.
Aranha, Andressa Borges
Hospital Escola de Grandes Animais, Faculdade de Agronomia e Medicina Veterinária (FAV), Universidade de Brasília (UnB), Brasília, Brazil.
Gomes Ramos, Maria Fernanda Bruno
Hospital Escola de Grandes Animais, Faculdade de Agronomia e Medicina Veterinária (FAV), Universidade de Brasília (UnB), Brasília, Brazil.
Oliveira, Edson Pereira De
Hospital Escola de Grandes Animais, Faculdade de Agronomia e Medicina Veterinária (FAV), Universidade de Brasília (UnB), Brasília, Brazil.
Dallago, Bruno Stéfano Lima
Hospital Escola de Grandes Animais, Faculdade de Agronomia e Medicina Veterinária (FAV), Universidade de Brasília (UnB), Brasília, Brazil.
Adorno, José
Burn Unit of Asa Norte Regional Hospital (HRAN), Brasília, Brazil.
Macêdo, Isabel Luana De
Hospital Escola de Grandes Animais, Faculdade de Agronomia e Medicina Veterinária (FAV), Universidade de Brasília (UnB), Brasília, Brazil.
Castro, Márcio Botelho De
Hospital Escola de Grandes Animais, Faculdade de Agronomia e Medicina Veterinária (FAV), Universidade de Brasília (UnB), Brasília, Brazil.
Campebell, Rita De Cássia
Hospital Escola de Grandes Animais, Faculdade de Agronomia e Medicina Veterinária (FAV), Universidade de Brasília (UnB), Brasília, Brazil.
Conflict of Interest Statement
The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
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