Tortoises are excellent pets and it’s only right to feel a little concern if you find your tortoise might not be in perfect health, but is it a natural process when a tortoise’s shell peels or is something more sinister going on?
“My tortoise shell is peeling” – Should I be worried? A tortoise regularly sheds skin and shell as she grows up. This process is slow, gentle, and happens naturally. However, if one or more large parts of a tortoise shell are peeling or they do so in a rapid manner, they might be sick or healing from injury. A visit to the vet is highly recommended.
So, let’s take a look at the tortoise’s shell and what can go wrong for your tortoise and how you can help if your tortoise is sick.
What Are Tortoise Shells Exactly?
A tortoise (and, indeed a turtle which is a fairly similar creature) will have a carapace (that is a top shell sometimes called a “dorsal” shell) and a plastron (that’s the bottom shell also known as the “ventral” shell) and both parts ought to be hard. (Though there are some species of turtle and one species of tortoise that have soft shells).
Interestingly, it appears that during the evolution of the tortoise the carapace and the plastron evolved completely separately from each other and then fused at a later date.
The two halves of the shell form a connection on the tortoise’s side that allow the shell to cover and protect the tortoise’s vital organs and most of the tortoise’s body.
The shell is made up of “scutes” which are the plate-like segments that cover the shell. They’re made of keratin which is what your hair and fingernails are made of. These sit over a layer of epithelium which then covers the bony shell beneath.
The “epithelium” is essentially a layer of skin from which the scutes can grow when they are meant to.
Why Might My Tortoise’s Shell Be Peeling?
There are two main reasons that your tortoise’s shell might be peeling:
- The tortoise is abrading their own shell – this is as a result of specific behavior and isn’t anything to worry about
- The tortoise is sick – many common tortoise diseases and parasitic infections can cause a tortoise to lose parts of the shell.
Related article: Tortoise Shedding: What’s normal and what isn’t
Your Tortoise Might Be Growing
As a tortoise grows the shell must grow with it. Otherwise, your tortoise would eventually burst like a balloon and that wouldn’t be much fun for you and it certainly wouldn’t be much fun for the tortoise.
So, one method to ensure growth is for the epithelium to grow new scutes which push their way outwards to replace the old scutes which, in turn, are forced from the tortoise’s body and this often looks like they are peeling prior to coming away.
This is absolutely normal. However, this does not happen to terrestrial tortoises. In contrast, a turtle is likely to shed scales at least annually using this process. This isn’t because turtles grow at a more rapid rate than tortoises (though it’s possible that some might). It’s because a turtle lives under the water.
Swimming around in water means that the shell is constantly exposed to biological attackers and if it wasn’t replaced regularly, the turtle would end up looking eroded.
A land tortoise (terrestrial tortoise) won’t shed its scales to grow. Unlike a turtle what it does is push the whole shell layer upwards and grow new scales as a bottom layer around the shell.
That means your tortoise isn’t shedding scales or peeling scales because it is growing unless you’ve bought a turtle rather than a tortoise by mistake.
Your Tortoise Might Be Sanding Their Shell
Your tortoise is not sneaking into your workshop at night to attack its own shell with sandpaper or a mechanical sander, but the shaving of a shell is sometimes down to the tortoise doing the equivalent thing naturally.
Tortoises are burrowing animals and they love to burrow and hide out underground. Now, depending on what they are burrowing into – sometimes, the substrate is going to start grinding against the shell as the tortoise moves in and out of it.
Related article: Why do tortoises bury themselves?
This can cause the tortoise to look a little abraded and you may find that little bits of the shell peel away because of it. This is not likely to be severe and it should be obvious that it’s happening because the whole of the shell will look slightly scratched as a result of the friction with the substrate.
This is very common in some tortoise species and, of course, in some areas with particular soil types. It’s normally nothing to worry about and while your tortoise will not shed and replace the damaged scutes – they aren’t damaged substantially enough for your tortoise to cause your tortoise any problems or put them at risk for infection.
Your Tortoise Might Be Sick
If natural and healthy causes are ruled out, then of course your tortoise might be shedding or peeling scutes due to illness. Let’s see how that happens and what we can do to get our tortoises back in shape!
What Diseases Might Cause Shedding In My Tortoise?
There are 5 common conditions which might cause a tortoise to peel or shed their scutes and they are Metabolic Bone Disease, Pyramiding, renal failure, shell rot (including ulcers and SCUD) as well as injury. Here’s what you need to know about each of them.
Metabolic Bone Disease
Metabolic bone disease is caused by a deficiency of calcium in the tortoise’s body and it can be extremely serious. If left untreated it can result in a fairly unpleasant end for your pet.
What causes it? Fortunately, because metabolic bone disease is very common in pet tortoises, it’s very well understood. There are three possible problems that can cause a deficiency of calcium in the tortoise’s body and they can occur separately or in some combination. They are:
- A direct deficiency of calcium in the diet. If there is too little calcium in the things that your tortoise eats – it can’t possibly metabolize enough calcium for its needs.
- A combination of phosphorous and calcium in the diet. Your tortoise needs both of these minerals in its diet. However, it needs a lot less phosphorous than it needs calcium. If there’s too much phosphorous in the diet – it will prevent your tortoise from effectively utilizing the calcium in its diet.
- A lack of Vitamin D3. Your tortoise can have enough calcium in its diet and in the right balance with phosphorous but without a supply of vitamin D3, the tortoise can’t use that calcium and it is effectively useless.
The symptoms of metabolic bone disease include:
- Softening of the shell
- Shedding or peeling of scutes
- Broken bones (calcium is also needed for bone development as well as shell development)
- Confusion and/or paralysis (calcium is also part of the tortoise’s nervous system)
How do you treat metabolic bone disease in tortoises?
If you think you’ve caught the problem early and can see very little damage to your tortoises and they’re not suffering from broken bones or paralysis, then you can take a two pronged approach to treatment.
Firstly, you need to increase their dietary supply of calcium. This should be fairly easy – find plants that contain high quantities of calcium, as a general rule of thumb these should be dark leafy greens (so no iceberg or romaine lettuce, for example). Your tortoises should get about 80% of their food intake from greens like these.
If you don’t feel that this is enough or you are already doing this, you can buy a powdered mineral supplement to add to their diet. However, be careful when using this – the calcium powder has an especially bitter taste and if you add too much, the tortoises won’t eat it. You have to balance their need for calcium with their taste buds.
This should, over time, address any deficiency of calcium and address any imbalance with phosphorous in the diet.
Secondly, you need to tackle the Vitamin D3 part of the equation and fortunately, this should be fairly easy. A tortoise is completely capable of making all the vitamin D3 that its body needs as long as you ensure that it has the tools to do so.
What it needs are light and heat. The light needs to contain UVB (Ultraviolet B) which means that if your tortoise lives indoors, you need a UVB bulb that they can bask under and you should wrap this bulb in a reflector to maximize the amount of UVB pointing at the tortoise. If they live outdoors, they will get this from sunlight (even when it’s overcast – UV rays reach the earth).
As for heat, if the tortoise is living outside, it should be getting the right temperature (though if it’s an imported species – you may need to check and if the temperature is too low, you may then need to move your tortoise indoors) but if your tortoise is indoors you should check the temperature in the living environment is correct for the breed and check the basking spots to see that they are about 10 degrees Fahrenheit warmer which is the ideal temperature for basking.
If, however, your tortoise does not respond to these treatments or it is showing more severe symptoms – you should take your tortoise to the vet. They can help with injections of vitamin D3 and/or calcium boosters.
Pyramiding is caused by an excess of protein in a tortoise’s diet. As a general rule, a tortoise should be fed an extremely low protein diet. Mixing cat food or dog food into a tortoise’s feeding bowl is an extremely bad idea. Both cat and dog food have too much protein to be healthy for a tortoise.
Related article: Can a tortoise eat cat or dog food?
It may also be related to calcium or Vitamin D3 deficiencies, the precise mechanism under which pyramiding occurs is not completely understood.
The symptoms of pyramiding are that the scutes end up pushed upwards and fattened to look like a pyramid. They can become damaged during this process and possibly peel or shed, though it is much less common to do so than with metabolic bone disease.
If you can see the scutes starting to come up and form pyramids, you must reduce the protein level in the tortoise’s diet and ensure that they are getting enough calcium and vitamin D3 (see the treatment for metabolic bone disease as to how this is done).
Once pyramiding occurs it cannot be undone or cured. However, given that it takes a long time for them to form – you ought to be able to catch it before it becomes too severe.
Fortunately, pyramiding is not considered to be dangerous to the tortoise, but it can prevent mating if it occurs with a female tortoise as it can prevent a male from mounting her successfully.
We did find a couple of accounts of tortoises losing their scutes due to kidney failure and though we couldn’t find out how common renal failure is in tortoises, we assume it’s fairly rare.
However, it makes sense that it might affect the scutes as when the kidneys fail, the level of phosphorous in the tortoise’s body will increase, and as we saw with metabolic bone disorder, too much phosphorous and the tortoise will stop being able to effectively utilize the calcium in their system.
So, you would expect the symptoms of this to be very similar to that of metabolic bone disorder. However, treatment for a tortoise’s kidneys can only come from a vet. Adding dietary calcium or ensuring adequate supplies of UVB are unlikely to bring relief by themselves.
Shell rot can be caused by a number of different conditions (bacterial, parasitic and sometimes, algal infections) and sometimes SCUD “septicemic cutaneous ulcerative diseases” is lumped in with these – however, SCUD is a much more serious problem (at least at first).
Shell rot causes ulcers on the epithelial layer below the scutes and these ulcers can then work their way through the shell causing severe damage.
If caught early, most shell rot can be treated with a program of cleaning plus medicine supplied by your vet. If things become more serious, however, very deep ulcers may need to be surgically repaired.
It is always best to talk to a vet if you think shell rot is a possibility, unlike with metabolic bone disorder, while the scutes may shed or peel or become soft, they will normally only do so in a specific area around the ulcer rather than more generally.
Your tortoise is not immune to being harmed by other animals, falling objects, etc. and any injury to the shell may cause the tortoise’s scutes to peel or shed.
These injuries, if minor, should always be cleaned and disinfected to prevent any infection. However, if the damage is substantial and reaches the epithelial layer below the scutes, you should seek a vet’s attention for your tortoise.
While a tortoise cannot regrow it’s scutes, they can often be repaired by a vet.
Can I Prevent Shedding From My Tortoise?
As you’ve seen the most important things to pay attention to are ensuring that your tortoise has the right level of calcium in their diet and is getting enough UVB to generate vitamin D3 in their bodies. If you ensure that this is the case, then most shedding or peeling will be avoided.
However, even the most careful tortoise owner can’t prevent injury 100% of the time and shell rot is always a possibility though you can reduce the likelihood of this be ensuring your tortoise is clean and well looked after and no tortoise owner can predict renal failure.
As you can see, when a tortoise starts to peel or shed scales, there are some genuine reasons to feel concerned. The good news is that as long as you take immediate action, almost all of these conditions are not particularly serious and can be expected to clear up quickly.
It is important that you do take action though as left untreated many of these problems can result in bigger problems, and they can even become fatal. If in any doubt regarding medical matters for your tortoise, always consult your vet as quickly as possible.