We recently had a tortoise injury ourselves, which took us on an educational journey into the reptilian body.
Reptilian skin is covered with scales that form armor. This armor makes it watertight and enables reptiles to live on land. This is in contrast to amphibians.
An important part of the skin is the horny epidermis. It has a thick stratum corneum. In it, waxes are arranged in membrane-like layers. In lizards and snakes, the whole skin is covered in overlapping epidermal scales. In turtles and crocodiles, it is covered in dermal scutes.
The cornified part of the epidermis is strengthened by β-keratin and sometimes α-keratin. In crocodiles and many turtles, the outer scale surface consists of β-keratin, and the hinge region contains α-keratin.
In lizards and snakes, both keratin’s form continuous layers with the α-keratin below the β-keratin. Some reptiles have developed a sensitive mechanosensory system in the skin.
The colors of reptile skin are produced by melanocytes and three types of chromatophores: melanophores, xanthophores, and iridophores. The color patterns are fixed, or the chromatophores give a rapid color change.
Their skin has a special feature. The epidermis is heavily keratinized with a layer. This layer also prevents water loss. This feature reflects their greater commitment to a terrestrial existence. Scales are found but are fundamentally different from the dermal scales of fish.
In reptiles, scales can’t be scraped off as in fish because they are an integral part of the skin.
The reptilian scale usually lacks the bony under the support of any significant structural contribution from the dermis.
It is a fold in the surface of the epidermis, an epidermal scale. The junction between adjacent epidermal scales provides a flexible hinge. If the epidermal scale is large and plate-like, it is also termed scutes.
Epidermal scales in different species can be overgrown. Skin protrusions can form in various regions. These include microornamentation, pits, sensory receptors, spines, horn-like processes, crests, scutes, plastron, carapaces, and some others.
The inner layer, stratum germinativum, consists of cuboidal dividing cells that produce the protein keratin.
The intermediate layer (stratum granulosum) has a lipid-rich film. This film plays a major role in providing a water-permeable barrier in the skin. The outer stratum corneum is heavily keratinized in scales.
Reptiles produce two forms of keratin. The first is α-keratin, which is flexible. The second is β-keratin, which provides strength and hardness. This type of keratin is unique to reptiles. β-keratin is found on the chelonian shells, while α-keratin is found in the hinges or between the scutes. Turtles and tortoises have special skin features.
There are free parts of the body, like the head, legs, and tail, covered with scales.
In a turtle, the skin’s appearance varies widely. It ranges from smooth skin, where scales are hardly visible, to thick and crusty skin. This variation depends on the turtle’s adaptation and way of life.
The turtle skin consists of the superficial part (epidermis) and the inner layer (dermis). Between these two layers, there is a basal lamina (BL). The surface layer consists of three layers: stratum basale, stratum granulosum, and stratum corneum. In the stratum basale, new cells proliferate. They replace old and dead cells. These cells are then pushed toward the surface of the skin.
Epithelial cells, keratinocytes, are found in the stratum corneum. They produce the protein keratin. Keratin plays a key role in reducing water loss. On the parts of the body that are more exposed to mechanical pressure, the keratinized layer is even thicker.
There are no blood vessels in the skin’s epidermis. The epidermal cells are fed by diffusion from the deeper layers of the skin through the BL.
Apart from keratinocytes in the epidermis, melanocytes and Langerhans cells are also located there.
The epidermis is developed from the ectoderm. It creates the BL. It retains water in the body. It also protects against infections and harmful external influences.
New cells created in stratum basale replace old and dead cells and suppress them at the surface of the skin. The skin dermis is derived from mesoderm and creates a reticular lamina (lamina reticularis). This layer contains many sensory nerves, including nerve endings and mechanoreceptors. It also has glands, blood vessels, and lymph vessels. Subcutis is fatty and slightly connective tissue,
In the turtle skin, horny plates are formed together with osteoderms.
Dermal bones are found below in the inner part of the skin (dermis). They grow together to gain more strength.
Corneal scales are made of water-insoluble keratin. This keratin is laid in an arrangement that allows a thin layer of skin between them. This makes it easier for the animal to move. In tortoises, the osteoderms grow together with the spine and ribs. They form the back of the armor, the carapace.
The back and abdomen of the armor, depending on the type of turtle, consists of several bones (shields). Above the bones (osteoderms), there is a layer of skin (epidermis). In turtles with a soft shell, such as the genus Apalone and the genus Dermochelys, this layer is “skinned.” In the other turtles, above the bony plates, there are also horny plates. These do not entirely match the shells’ strength and ability to regenerate.
What does this have to do with Tank and his injuries?
Many captive turtles have roughened, pitted keratin layers with areas of keratin loss or thinning and/or thickening. This change is usually limited to the keratin layer but invades into deeper bone structures.
Traumatic lesions can turn infectious. The ulcerating disease is classified as superficial or deep. Superficial ulcerations involve the keratin layer and minimally invade bone.
An infectious bacteria, Benekea chitinovora, has been described in cases of progressive superficial shell lesions. These lesions lead to mortality in freshwater turtles. Shell or skin trauma was the proposed route of inoculation.
Septicemic cutaneous ulcerative disease (SCUD) syndrome has been described; shell lesions lead to systemic bacterial infection with Citrobacter. Lesions of any type that start superficially progress to invade deeper regions of the bone or lead to sepsis.
Deep bone lesions result from an uncontrolled superficial lesion. They can also develop within the shell bone itself. The keratin and even outer bone layer is normal until the disease is extensive.
Tank has managed to fight his infection with medications. He is now in the process of building new keratin.
Click this link to read a fascinating study on electromagnetic waves and the healing of reptiles…
Here is a video of Tank before the infection. We thought it was broken, and we were so happy when it started to move. It was afterwards, while trying to confine him in a smaller stall, that he broke his toenail. That is what began the terrible road he is still fighting to heal from.
Tank was facing amputation due to an infection he was fighting after his nail broke. He would not stay still despite the injury and intense swelling. We even put him in a small stall on the advice of the vet. You just can not keep a strong tortoise down.
Still, the bill was going to be more than $2,000!
Thank you to our supporters. You helped us raise more than enough money. We can now pay for his medications and medical service needs!
Thanks to Dr. Ivan Alfonso and Sr. Vet Tech Joel Diaz, Tank is keeping his leg but is still currently healing.
But one of the donation checks was a scam!
Read the post we wrote. We were still hoping it was all a mistake. We thought the check would still be good (pretty naive)
Because he did not need the expensive surgery, we had a much lower bill. But it was still an exotic animal bill, and none of those come cheap.
We raised the needed funds thanks to plant sales and wonderful support through donations on GoFundMe, Facebook, and Paypal. Yet, the whole thing with this “John Henry” bad check made us go just $6.83 in the negative. BB&T charged us $36 because of this insufficiency.
We will never give up on these animals!
As of today, Tank has very little bone exposed because the keratin is forming.
This is the best outcome for the situation and shows just how resilient these reptiles are.. Click here to read more about his story.
People ask us all the time who we trust, and we always suggest the next vets…
FloridaWild Veterinary Hospital In Deland
Bush Warriors Wildlife Conservation in Jupiter
Affiliated Veterinary Specialists – Orlando
And now our personal favorite and most recommended, and the name will make you say hmmm
Mobile Veterinarian Services. These doctors come to you if you need it and can afford it. If it’s not feasible, which often happens with us, drive a short distance to their location.
For these two doctors that we have grown to trust the most, this means various offices. Most of the time it is a main office located in the Four Corners area of Clermont. Still, if another hospital needs them, they are… well, mobile.
We will share more about how to find them with anyone who wants to know. Just contact us through messenger, and we will share where they are and how to contact them.
Until then, we are so blessed that they consider themselves the facility’s primary veterinarians. On-call whenever we need them.
Check out Tank during his treatment….
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