Tortoise Shell Rot (Causes, Prevention, Treatment)

What Is Tortoise Shell Rot?

Shell rot or ulcerative shell disease is an infection to a tortoises shell. It occurs when bacteria, fungi, or algae infects the blood vessels of their shell. Tortoise shell rot can effect the carapace and the plastron of the shell and it’s mainly caused by the tortoise living in a dirty environment that doesn’t get regularly cleaned.

Bacteria thrives in these conditions thus making it possible for a tortoises shell to become infected. Shell rot is also more likely to occur when your tortoise is poorly and their immune system is compromised, as they will struggle to fight bacteria.

Let’s look at how to recognize the symptoms of tortoise shell rot so you can stop it before any damage is done.

What Are The Symptoms Of Tortoise Shell Rot?

The longer that infection exists in the tortoise, the more damage will be done as the infection spreads into the deep tissue. To recognize shell rot in your tortoise look out for the following symptoms :

  • Smelly discharge coming from the shell
  • The shell plates appearing soft or lifting off
  • Red coloured fluid being visible the plates of the shell
  • Soft areas or pitting under the surface of the shell
  • Shell appearing cracked

Shell rot must be treated as soon as you recognize the symptoms as it can lead to deep-seated shell abscesses which would require surgical intervention if left untreated.

It’s also a highly contagious infection which means if you keep multiple tortoises together it’s likely to spread rapidly. If you notice the signs of shell rot you should contact a vet to prevent it getting worse and harming multiple tortoises.

What Are The Causes Of Shell Rot In Tortoises?

Shell rot can be caused by a number of things therefore it may be hard to pinpoint where they have got it from, it could be from a tortoise that’s infected or a number of other factors including :

  • During a fight
  • Wrong substrate humidity
  • Ticks
  • Metabolic bone disease
  • Through an open cut

During A Fight

It’s possible for two tortoises to be aggressive with each and fight, particularly two males or one male and one female. Tortoises can be pretty rough with others for different reasons and beat up another one. It’s common for them to target just above the tail, and this is where shell rot is often found.

To avoid this don’t keep two males together, or have two different species of tortoise in the same environment as they’re likely to fight with each other.

Wrong Substrate

Dirty and incorrect substrate is often found to be a factor in shell rot occurring. If a tortoise from a humid environment is able to over-dry their skin and shell will suffer problems because of it. On the other end of the spectrum, if tortoises from desert environments are provided with a damp substrate the keratin can become soft and distorted allowing bacteria a chance to infiltrate.


Ticks are blood-sucking parasites that are able to pierce a tortoises skin quite easily and attach onto them. This causes the entry for shell-rot pathogens to infect your tortoise. There is a higher chance in your tortoise getting ticks if they’re kept outside but indoor tortoises aren’t immune to them.

Metabolic Bone Disease

Your tortoise’s shell is more likely to be infected if they already have existing shell problems. MBD is a group of bone and shell problems most commonly caused by a calcium/phosphorous imbalance due to a bad diet. As a result of metabolic bone disease the tortoise will take calcium from its bones in order to make up for the loss, which leads to a number of health problems including shell rot.

Through An Open Cut

An open cut provides perfect conditions for pathogens like shell rot to infest your tortoise. If your tortoise has previously suffered an injury that’s caused a crack in the shell bacteria can form between them leading to shell rot.

Open cuts are able to occur via a number of different ways such as :

  • Tortoises fighting
  • Sharp objects
  • Incorrect humidity or temperature causing dryness

Now you’re aware of the symptoms and causes of shell rot let’s look at how we can prevent it.

How Do You Prevent Tortoise Shell Rot?

Taking the right measures to prevent shell rot will save you a ton of stress and money compared to having to treat shell rot taking your tortoise to a vet.

While shell rot may not be completely avoidable there are a few precautions you can take to limit the chances of your tortoise being infected, they are :

  • Regularly clean your tortoises living environment
  • Remove sharp objects
  • Ensure the correct humidity and temperature
  • Don’t keep tortoises together
  • Introduce a well-balanced diet

Regularly Clean Your Tortoises Environment

As shell rot is bacteria that thrives in dirty conditions, regularly ensuring your tortoises enclosure is clean will limit the spread. Cleaning a tortoises living space is not only important for eliminating shell rot, but it can reduce the chances of your tortoise spreading salmonella around if they’re infected with that.

You should clean out your tortoises enclosure every 2-3 weeks, along with changing the bedding. Be sure to use a cage cleaner or disinfectant, avoid soap or detergents as they are known to be harmful to tortoises.

Remove Sharp Objects

Sharp objects present in a tortoises cage can cause a number of problems for them. Your tortoises scraping their shell off it and leaving an open wound would increase the likelihood of shell rot and other nasty infections.

Looks out for sharp rocks, or pieces of wood that your tortoise can cut themselves on and remove them.

Ensure The Correct Humidity And Temperature

Your tortoise living in incorrect humidity or temperature conditions can do damage to their shell that leads to shell rot. To prevent this you need to ensure the temperature and humidity is optimal for the chosen species.

Tortoises live in different areas across the globe, therefore they will have different needs. A Hermann’s tortoise will require a totally different temperature than a Sulcata tortoise as they live in different climates.

Don’t Keep Tortoises Together

Keeping tortoises separately, particularly two males or a male and a female can help prevent tortoises from getting shell. This is because of two reasons.

Two tortoises kept together will likely fight and cause wounds for shell rot pathogens to seep through.

Also, as shell rot is contagious there is a higher chance of it being spread if there are other tortoises to spread it to.

Introduce A Well-Balanced Diet

As shell rot is a form of Metabolic bone disorder, you can help prevent it by feeding your tortoise a well-balanced diet with an appropriate calcium to phosphorous ratio.

Tortoises are herbivores and therefore require a diet high in fiber and calcium, but low in fats and protein.

These foods include plants, vegetables, greens, and fruit on occasion. As MBD is most commonly caused by a lack of calcium it’s good practice to sprinkle some calcium supplement on your tortoises food a couple of times a week.

A well-balanced diet isn’t only helpful for preventing shell rot but it’s paramount in providing your tortoise with a long and healthy life free of disease.

How Do You Treat Tortoise Shell Rot?

Sometimes prevention isn’t enough, you could introduce all the precautions above and your tortoise could still develop shell rot. It’s not all doom and gloom though as shell rot can be treated, the earlier the better.

There are a few things you can do at home before seeking professional help :

  • Povidone-iodine or chlorhexidine solution
  • Keep the shell dry
  • Antibiotics
  • Clean the shell

Povidone-iodine or chlorhexidine solution

For a mild case of shell rot a chlorhexidine solution can be used to get rid of the infection. The solution kills off any existing bacteria on the shell and halt it from getting worse.

Twice a day, take a toothbrush with the solution and scrub the affected area, ensure you’re scrubbing vigorously don’t be afraid of hurting them. To note, it’s important you keep them dry afterwards as shell rot properties are anaerobic meaning they thrive off water.


In cases where the infection has made it’s way into the blood antibiotics may be required to treat it. This is usually an antibiotic cream used on the affected area.

Clean The Shell

Shell rot is bacteria therefore you should clean your tortoises shell in an attempt to get rid of it. If the infection is still new cleaning their shell might be a efficient way of eliminating the pathogens before they really take hold.

If the treatments above fail to treat shell rot, it’s time for a trip to your vet.

Can Tortoises Feel Shell Rot?

There use to be a common myth that tortoises couldn’t feel their shell which brought upon almost torturous acts by the people of that time. As the science came along it was discovered that there were thousands of nerve endings in a tortoises shell. This means tortoises can not only feel their shell, but they are extremely sensitive to it.

As there are many nerve endings tortoises can feel shell rot, infections, and other injuries that may happen to their shell.

Tortoise Shell Rot – Final Thoughts

Tortoise shell rot is when a tortoises blood vessels in the shell are infected with pathogens or bacteria. The signs include a potent smell coming from the shell, red fluid on the shell plates, and pitting under the surface of the shell.

It’s contagious and therefore easily spread to other tortoises, shell rot is a serious infection and not one that should be overlooked. Tortoise shell rot can be prevented by practicing good hygiene habits e.g. regularly cleaning a tortoises enclosure, using the right substrate, and monitoring any cuts or cracks your tortoise has.