Turtle Shell Rot – Causes, Symptoms, Treatment & Prevention

Shell rot is an issue many turtle owners face at some point. Find out what are the symptoms and causes of shell rot, how to treat it, and more importantly how to prevent it from happening again in the future.
Turtle Shell Rot

What Is Turtle Shell Rot?

Shell rot is the visible effect of a fungal or bacterial disease on a turtle’s shell.

It can affect the upper shell (called the carapace) or the shell underneath your turtle (called the plastron).

Turtle Shell Rot on Carapace and Plastron
Shell Rot On Carapce (left) & Shell Rot On Plastron (right)

What Does Turtle Shell Rot Look Like?

A healthy turtle shell should have uniform darkness to it.

Shell rot appears as pale white or grey patches on the carapace or plastron which are soft to the touch and will eventually look as if they’re sinking into the shell or pitting.

There may also be a reddish-colored fluid under the plates (scutes) of your turtle’s shell.

These affected areas will give off an unpleasant-smelling discharge once the shell rot is advanced.

Turtle Shell Rot Symptoms

The symptoms of shell rot are:

  • White or grey patches on the upper and lower shell
  • Reddish fluid visible under plates of the shell (scutes)
  • Flaking of the scutes
  • Scutes may start to lift
  • Soft areas and pitting on the shell
  • Smelly discharge in affected areas

What Causes Turtle Shell Rot?

Now you know what shell rot is, and what it looks like, let’s go over the causes.

The 4 main causes of shell rot in pet turtles are:

1. Dirty Tank Water

Turtles are messy critters and their tanks can soon resemble a swamp and get pretty smelly if you don’t have good quality filtration.

Aquarium filters are generally rated for keeping fish. A pet turtle needs much better filtration than fish because they create much more waste.

You need a filter that can handle at least 2-3 times the volume of water in your tank. If you have a 50-gallon turtle tank, get a filter rated for 150 gallons.

A canister filter is by far the best option for keeping a turtle tank clean.

Fluval 407 (Left) Fluval FX6 (Center) Polar Aurora 4-Stage 525GPH (Right) are amongst the best canister filters for a turtle tank

Check out my best filter for a turtle tank post where I’ve reviewed all the best options available.

Tank filtration alone isn’t enough, you also need to establish a nitrogen cycle, regularly clean the tank, and perform water changes.

2. Inadequate Or No Basking Area

You need to provide turtles with a suitably sized basking area equipped with heat and UV lighting.

Turtles bask in sunlight naturally in the wild to dry off their shells and absorb UV light.

Pet turtles are generally kept indoors so you need to provide:

  1. A basking platform that stays dry.
  2. A heat lamp to dry off their shell properly.
  3. A UVA/UVB lamp so they can absorb enough UV light.

A basking platform should be kept dry at all times and not be submerged in the water or get wet from spray bars.

UVA light is needed to help your turtle’s immune system, mood, metabolism, breeding health, and general activity levels throughout the day.

UVB light helps them produce vitamin D3 which metabolizes the calcium in their diet to keep their bones and shells healthy.

A heat lamp warms your turtle up and allows them to dry out, helping prevent fungal infections.

3. Damage To Turtles Shell

This could be caused by other turtles in the tank.

You may need to look at upgrading to a larger tank or separating the turtles completely.

Damage to a turtle’s shell can also be caused by sharp objects in the tank. 

Do you have any large pointy rocks that your turtle may be bashing into? If so, it’s best to remove them to avoid any further damage.

4. Ticks

This tends to be more of an issue for tortoises rather than turtles.

But, if you take your turtle outside to bask and roam around the garden, always check for ticks once you bring them back inside.

How To Treat Shell Rot At Home

If you’ve caught the shell rot early enough you should be able to treat it at home.

The first thing to do is to figure out, and fix if you can, what’s causing the shell rot:

  • Dirty tank water?
  • No basking area?
  • Damage to shell from tankmate?
  • Sharp objects in the tank?
  • Tick?

Once you’ve fixed the underlying cause you can move on to the treatment stage.

Treatment works best if you can limit the amount of time your turtle is in its (cleaned) tank.

Put them in their tank for 1-2 hours per day to eat and go to the bathroom.

Make sure you provide them with a shallow dish of water for drinking when they are out of their tank.

Turtle Shell Rot Treatment

You’ll need the following items to treat your turtle:

Once you’ve got all of the above items, you should follow the steps below:

Step 1:

Remove the turtle from the water, so it can be kept dry whilst you are treating it.

Step 2:

Debride (remove) any dead areas of the shell by gently scraping them with a scalpel. 

If it doesn’t come away easily, leave it as you may harm your turtle.

Ask a vet to do this if you don’t feel confident or skip to the next step.

Step 3:

Gently clean all of your turtles’ shell with warm water and a toothbrush, to remove any dirt or algae.

Rinse your turtle well with clean water.

Step 4:

Thoroughly dry your turtle with a towel or allow it to air dry.

Step 5:

Carefully apply the betadine or povidone-iodine solution to infected and surrounding areas.

Keep the turtle in a clean tub away from water to allow the treatment to fully dry and be absorbed.

Top Tip: Be careful not to spill these products when using them, as they stain everything!!

Step 6:

Apply silver sulfadiazine cream to affected areas (optional)

Step 7:

Allow your turtle to bask under a UV and heat lamp or put it out in the sunshine for 30 mins per day.

If your turtle isn’t warm enough, its body won’t heal.

Step 8:

Repeat this process once or twice a day, it can take a few weeks to fully heal.

When To See A Vet

Red-Eared Slider at the vet

If there is a smelly discharge you need to contact a vet ASAP as it could have progressed into severe turtle shell rot and will need stronger medication.

If not treated quickly shell rot can turn to SCUD which is a much more serious condition and can prove fatal.

If you follow the home treatment steps above and don’t see any improvement within a week or so contact a vet as they can provide stronger medication.

I’ve left a link to where you can find your nearest turtle vet at the bottom of this post.

How To Prevent Shell Rot

You can prevent your pet turtle from getting shell rot by:

  • Having a good quality water filter
  • Regularly clean your turtle tank and change the water
  • Provide a basking area with both heat and UV lights
  • Removing sharp objects from your turtle tank

If you’ve more than 1 turtle in your tank it could be that the tank is too small and they’re bumping into each other, or they could be fighting over territory.

If that’s the case, upgrading to a bigger tank may resolve the issue, or you may have to keep your turtles in separate tanks.

I have listed some great turtle tank options in my best tank for red eared slider post.

Turtle Shell Rot FAQ

A few questions that get frequently asked about turtle shell rot are:

Turtle Shell Rot Or Shedding?

Turtle shedding vs shell rot
Turtle Shedding – image courtesy of steve loya Flickr (left) vs Turtle Shell Rot (right)

A healthy turtle shell will shed scutes naturally as the turtle grows.

When shedding, the scutes should come off whole and are so thin they’re almost see-through.

Please don’t ‘help’ your turtle shed by pulling off any peeling scutes, as this can be painful for them. Leave it to happen naturally.

Shedding will last for a few weeks and will happen periodically, whereas shell rot won’t go away until you treat it.

How Do You Know If A Turtle Has Shell Rot?

You’ll know your turtle has shell rot if they have pale white and grey soft patches that over time start to sink into the shell carapace or plastron. 

Often this will be accompanied by a bad-smelling discharge.

Can Shell Rot Kill Turtles?

Yes, shell rot can kill a turtle if it’s not treated.

Severe turtle shell rot can turn into SCUD which can be fatal for a turtle.

Is Shell Rot Contagious?

Yes, shell rot can be contagious and you should isolate your turtle from any other turtles as soon as you spot any symptoms.

Closing Thoughts On Turtle Shell Rot…

Hopefully, you won’t have to deal with shell rot in the future, if you put in place the steps above to help prevent it.

If you are unfortunate enough to have to treat it, you’ve now got all the knowledge you need so your turtle can recover as quickly as possible.

Check out my turtle’s section for in-depth product reviews and tips on keeping your pet turtles happy and healthy.

Should your turtle need to see a vet, you can find your local turtle vet here.