Low temperatures reduce skin healing in the Jacaré do Pantanal (Caiman yacare, Daudin 1802)

Leandro Nogueira Pressinotti,Angela Paula Alves De Lima,João Carlos Shimada Borges,José Roberto Machado Cunha Da Silva,Bruno Cogliati,Ricardo Moraes Borges,Renata Stecca Iunes,Victor Manuel Aleixo

doi:10.1242/bio.20135876

Abstract

SummaryStudies of skin wound healing in crocodilians are necessary given the frequent occurrence of cannibalism in intensive farming systems. Air temperature affects tissue recovery because crocodilians are ectothermic. Therefore, the kinetics of skin wound healing in Caiman yacare were examined at temperatures of 33°C and 23°C. Sixteen caiman were selected and divided into two groups of eight maintained at 23°C or 33°C. The studied individuals' scars were photographed after 1, 2, 3, 7, 15 and 30 days of the experimental conditions, and samples were collected for histological processing after 3, 7, 15 and 30 days. Macroscopically, the blood clot (heterophilic granuloma) noticeably remained in place covering the wound longer for the caiman kept at 23°C. Microscopically, the temperature of 23°C slowed epidermal migration and skin repair. Comparatively, new blood vessels, labeled using von Willebrand factor (vWF) antibody staining, were more frequently found in the scars of the 33°C group. The collagen fibers in the dermis were denser in the 33°C treatment. Considering the delayed healing at 23°C, producers are recommended to keep wounded animals at 33°C, especially when tanks are cold, to enable rapid wound closure and better repair of collagen fibers because such lesions tend to compromise the use of their skin as leather.

Highlights

Crocodilian wound healing and tissue regeneration processes are still poorly studied
Summary Studies of skin wound healing in crocodilians are necessary given the frequent occurrence of cannibalism in intensive farming systems
The kinetics of skin wound healing in Caiman yacare were examined at temperatures of 33 ̊C and 23 ̊C

Summary

Introduction

Crocodilian wound healing and tissue regeneration processes are still poorly studied. There are reports of the tail tip and lower jaw having a partial regenerative capacity. Several components that may affect the regenerative process have been reported, including innervation, the contact between the epidermis and the lower layers of the skin and muscle layer and, the environmental temperature (Alibardi, 2010). A study of the effect of temperature on the regeneration of the tails of Anolis carolinensis lizards indicated that the tail grew longer and faster at 32 ̊C than at 21 ̊C (Maderson and Licht, 1968). There have been no reports on the effect of temperature on crocodilian wound healing

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