Why Tortoises Get Shell Rot and How to Treat It

More often than not, shell rot in tortoises is the direct result of bacterial exposure. Tortoises may be exposed to bacteria from dirty environments, such as their substrate/bedding, or dirty water. Not cleaning the enclosure of your tortoise properly or regularly may ultimately lead to shell rot

Bacteria thriving in a dirty environment is the most common reason for shell rot, but it’s not the only one. You should be aware of what might cause shell rot so you can preempt and prevent any undue suffering. Here we’ll look at why shell rot occurs, how to avoid it, and how it can be treated.

It’s important to note that both the plastron (lower ‘belly’ of shell) and carapace (upper shell ‘dome’) can suffer the effects of shell rot.

Why Does Shell Rot Occur in Tortoises?

  • Bacteria

Living in a dirty environment is not something any tortoise should have to endure. Apart from being unhygienic and posing a general health risk, it can also lead to shell rot, which can indeed be life threatening. Moldy bedding substrate, or water that has been contaminated with dirt and feces, for instance, can be a source of bacteria.

From here bacteria can potentially infect blood vessels within the shell of the tortoise through small wounds or abrasions that you may not even be aware of. In time you may notice small areas that look as though they have been eroded or ‘moth eaten’ as rot sets in.

As the condition worsens, there may even be a bloody discharge. The scutes (plates that make up the shell) may start falling off when the bacteria infection is severe enough, and this will reveal the nerves and bone that lie underneath. At this point, as well as suffering the complications of infection, a tortoise would likely be considerable pain from wounds of this nature.

  • Metabolic Bone Disease

It is also possible for MBD, aka metabolic bone disease, to be the cause of shell rot. This occurs when there is insufficient vitamin D and calcium intake, and UVB ray exposure. As a result, the bones lose a lot of calcium, and the shell is and gets softer and may become malformed, ultimately leaving it vulnerable to damage and infection.

  • Shell Damage

Yet another common culprit in shell rot occurrence is shell damage. If your tortoise suffers an injury or trauma resulting in a fracture or other damage to the shell, bacteria grow in the cracks that were created, causing the rot issue.

It’s worth noting that shell damage might happen for a number of different reasons. Perhaps a less obvious cause is incorrect temperature or humidity. If you don’t get the levels of these conditions right, in time cracks are likely to appear in your tortoise’s shell.

If there are any sharp items in the tortoise table or vivarium, they might also end up causing shell damage. Tortoises tend to climb on top of anything they can access within their enclosure, and depending on what this is, it could well result in damage to the plastron in particular.

Lastly, a fight between two tortoises may also end badly for the tortoise (or tortoises), particularly with regard to the shell. If you have multiple tortoises, then they might start fighting in some cases (usually between two males), and this may lead to shell cracks. This is one of several reasons why it generally isn’t recommended to keep two tortoises in the same enclosure.

How Can You Avoid It?

If you want to make sure your pet tortoise doesn’t have to suffer from shell rot in the future, there are a few things you can do for prevention.

  • Clean Their Enclosure Regularly

Regularly cleaning your tortoise’s cage is mandatory. Maintaining a proper cleaning routine is good practice for a variety of reasons, not least that it prevents bacterial and other parasitic infection causing health issues such as shell rot. So, if you’re not already doing it, make sure to keep your enclosure clean, ideally with a full substrate replacement and full clean every two to three weeks, and daily removal of obvious soiling.

  • Keep the Right Humidity and Temperature

You should always keep an eye on the temperature and humidity in your tortoise’s enclosure. As discussed above, if there aren’t proper conditions in this regard, the shell may in time start to crack.

Take proper measures to ensure the temperature isn’t too high or low with the correct heating and temperature monitoring strategy, and likewise regarding humidity.

  • Avoid Adding Sharp Objects to the Enclosure

Whether your tortoise has already suffered with shell damage or not, it’s best to examine the enclosure to prevent any issues in future. Are there any sharp objects inside, for example pieces of wood or other scenery items? If you see anything that you consider might be dangerous for the tortoise, get rid of it.

Complications that May Arise as a Result of Shell Rot

When a tortoise’s shell gets damaged, there may be further complications that only serve to reiterate why it is so important to avoid it in the first place.

As mentioned above, shell rot can lead to disintegration and damage to the shell, much of which may never fully recover.

Perhaps more alarmingly, once the bacteria that leads to shell rot sets in, if left untreated the infection can lead to blood poisoning and septicemia, which can quickly be fatal if left untreated.

How to Treat Shell Rot

Fortunately, shell rot can be treated, and your tortoise can go back to living a happy life. Here are some things you can do to treat the tortoise and aid the healing process:

  • Keep Them Away from Water and Attacking Tortoises

When dealing with a very mild case, the shell may be heal, but it must be kept dry in the meantime. The only exception is when you’re cleaning the shell, but otherwise, make sure they are not around water.

Moreover, if the damage to the shell came about after your tortoise was attacked by another tortoise, then clearly they should be kept apart from that point forward.

  • Clean the Shell

Using a soft bristle brush, scrub off potential algae or dirt from the shell. This should clean any large pieces of debris from the shell. Then, give the tortoise a nice soak and wipe off any residual grime. In cases where infection has yet to take hold this can be an effective means of suppressing it.

  • Get Rid of the Bacteria

Chlorohexidine solution can be used to clean any suspect abrasions on the shell of a tortoise. It will help kill bad bacteria and prevent the issue from getting worse.

Some consider hydrogen peroxide a solution too, but in reality, this will only slow down the healing process as it doesn’t only kill bad bacteria, but also damages healthy cells.

  • Use Healing Cream

Healing cream is an alternative mild medical intervention. Silver sulfadiazine cream is the best solution and will aid the healing process. Triple antibiotic creams will also come in handy. If you want to make the best out of this treatment, apply it several times a day to all infected areas.

What to Do When the Situation Is Out of Control

While you might be able to treat less severe cases of shell rot, very advanced cases should only be treated by a professional. If you’ve been treating your tortoise but see no improvement after a few days, or if you’re in any doubt at all how ill your tortoise is, you should seek assistance from a vet. If not, your tortoise might develop the aforementioned septicemia, or SCUD, (aka Septicemic Cutaneous Ulcerative Disease), so it’s certainly not worth the risk.

If necessary your vet will be able to give your tortoise more aggressive antibiotics to aid the healing process and prevent dangerous complications.


If your pet tortoise suffers from shell rot, or you’re worried they might in future, we hope that this article was useful. Now you know what the possible causes are, you can use these tips to prevent or treat shell rot in your tortoise, hopefully helping to keep them in good health for many years to come.

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