We recently had a tortoise injury himself which took us on an educational journey into the reptilian body.
Reptilian skin is covered with scales forming armor that makes it watertight and enables reptiles to live on land in contrast to amphibians.
An important part of the skin is the horny epidermis, with thick stratum corneum in which waxes are arranged in membrane-like layers. In lizards and snakes, the whole skin is covered in overlapping epidermal scales and in turtles and crocodiles 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 containing α-keratin.
In lizards and snakes, both keratins 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 may be fixed or the chromatophores may provide rapid color change.
The main special feature of their skin is that the epidermis is heavily keratinized with a layer, which also prevents water loss. This feature reflects their greater commitment to a terrestrial existence. Scales are present but are fundamentally different from the dermal scales of fish.
In reptiles, scales cannot 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 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 and skin protrusions can be formed in different regions, such as microornamentation, pits, sensory receptors, spines, horn-like processes, crests, scutes, plastron, carapace, 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 that plays a major role in providing a water-permeable barrier in the skin. The outer stratum corneum is heavily keratinized in scales.
Two forms of keratin are produced in reptiles: α-keratin, which is flexible, and β-keratin, which provides strength and hardness and is unique to reptiles. β-keratin is found on the chelonian shells, whereas 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, such as the head, legs, and tail, covered with scales.
In a turtle, the skin’s appearance varies from smooth skin, where we can hardly see scales, to thick and crusty skin, which depends on the adaptation and the 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 and replace old and dead cells and push them toward the surface of the skin.
Epithelial cells, keratinocytes, which are found in the stratum corneum, produce the protein keratin, which plays a key role in reducing the loss of water. On the parts of the body that are more exposed to mechanical pressure, the keratinized layer could be even thicker.
There are no blood vessels in the skin epidermis, so the epidermis 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 ectoderm, creates the BL, and has the function of retaining water in the body, as well as the protection 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). In this layer, there are many sensory nerves (nerve endings and mechanoreceptors) as well as 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) and they grow together to gain more strength.
Corneal scales are made of water-insoluble keratin, which is laid in the arrangement allowing a thin layer of skin between them that makes it easier for the animal to move. In tortoises, the osteoderms are grown together with the spine and ribs, thus forming the back of the armor, carapace.
The back and abdomen of the armor, depending on the type of the turtle, consists of several bones (shields). Above the bones (osteoderms), there is a layer of skin (epidermis) which is in the turtles with soft shell (the genus Apalone, the genus of the turtle Dermochelys) “skinned.” In the other turtles, above the bony plates, there are also horny plates, which 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 may invade into deeper bone structures.
Traumatic lesions can turn infectious. In fact, the ulcerative disease may be 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 leading 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 begin superficially may progress to invade deeper regions of the bone or lead to sepsis.
Lesions deep in the bone may be the result of an uncontrolled superficial lesion, but can also develop within shell bone itself. The keratin and even outer bone layer appear normal until the disease is extensive.
Tank has been able to fight his infection thanks to medications and is now in the process of building new keratin.
Click this link to read a fascinating study on electro waves and the healing of reptiles… https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3637559/
Here is a video of Tank before the infection. We thought it was broken and we were so happy when he started to move it. 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. What happened was he would not stay still even after the injury and intense swelling, This was even after we 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 two $2,000!
Thank you to all of our supporters who helped us raise more than enough money to 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!
Check out the post we wrote when we were still sort of hoping it was all a mistake and the check would still be good… (prettty 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.
It was because of plant sales as well as wonderful support through donations on GoFundMe, Facebook, and Paypal we raised the needed funds and the whole thing with this “John Henry” bad check made us go just $6.83 in the negative. BB&T did charge 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 following vets…
And now our personal favorite and most recommended and the name will make you say hmmm
Mobile Veterinarian Services. These dorctors come to you if you need it and can afford it. And if that is not a possibility as it is with us most of the time, you just have to make a short drive to where they are.
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. However, if another hospital needs them, they are… well mobile.
We will share more about how to find them to 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 facilities’ primary veterinarians. On-call whenever we need them.
Check out Tank during his treatment….
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