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Turtle First Aid – Shell Sores or Holes in Shell

My turtle has sores or holes on it’s shell

Shell Sores and Holes

Shell sores and holes are a frequent problem in turtles, but one that you must deal with quickly. Oftentimes, they can in fact be a sign of an infection or injury that needs some prompt attention.

As it is alive, the shell is a good reflection of the animal’s overall health. Therefore, we must take any changes to its appearance seriously. Despite its solid feel, the shell is a living structure, with nerves, bone, blood supply and a keratinous outer layer. It can feel its surroundings and plays vital roles in turtle biology.

Its primary role is of course protection against predators. I probably don’t need to point this one out to you! Other roles that it fills are those of a physical barrier against germs, and as a site to produce blood cells, to name just a couple.

Sometimes, sores and holes may appear on the shell from an infection, which can represent the culmination of an overall decline in your pet’s health, diet, or living conditions. On other occasions, these symptoms can instead simply be the result of an injury. When this occurs, treatment can be both successful and short-term.

Whatever the case may be, this article will give you guidelines on how to decide on what to do next. Keep reading to find out what could be the cause, when a shell sore or hole is a problem and when to see a vet.

Common causes of shell sores and holes

Turtle Shell Sores
Turtle with Shell Sores

I wish there were just one answer for this! Unfortunately, there are several causes for this issue, so it’s best we take a minute to understand each of them. Let’s take a look…

Shell rot

This is the main culprit! Also known as Ulcerative Shell Disease, Shell Rot is something that can crop up whenever poor husbandry weakens a turtle’s immune system, or the animal is injured by an unsafe enclosure.


Injuries are another common cause, though usually easier to identify than Shell Rot. If pink tissue is exposed, or bleeding is occurring, you’ve got an injury on your hands. Check out the treatment section later in the article to find out what to do.

Algal Shell Disease

Algal Shell Disease is a strange infection that occurs in mud turtles, being most common in the Yellow Mud Turtle (Kinosternon flavescens). It is essentially an uncommon form of shell rot caused by an alga known as Arnoldiella chelonum.

This alga anchors itself to the pores of the shell scutes and digs down to the bone, leaving holes that look about the size of a bb pellet. Though it sounds awful, the truly strange part is that it doesn’t appear to do much long-term damage to most Mud Turtles.

Personally, I would not try to “treat” a Mud Turtle with algal growth and a hole or two in its shell. I would instead get a pump with UV filter to help kill the algae in its water. In addition, I would make sure it had a completely dry basking spot and consider brumating it in dry conditions.

I say this because several dedicated researchers have found that Algal Shell Disease retreats and improves when the algae are dried out or occurring in small numbers.

Holes drilled by humans

This is a practice your grandparents might remember… Years ago, when people wanted to prevent their pet Box Turtle or Tortoise from escaping, they would drill a hole through its shell and put a chain through.

These days we obviously know better. An act such as this was cruel in the extreme, and undoubtedly came from a lack of education. Nonetheless, you can still occasionally find old Box Turtles with a perfectly round hole in the edge of their shell.

If you’ve recently rescued one and notice a hole that matches this description, then it is possible it is an elderly animal that someone mistreated many years ago.

When is a Shell sore or hole a problem?

A Large-nosed Wood Turtle (Rhinoclemmys_nasuta) with some unusual sores on its shell
A Large-nosed Wood Turtle (Rhinoclemmys_nasuta) with some unusual sores on its shell – source

If you spot a sore or hole on your turtle’s shell there are two things you need to ask yourself: is it new, and is it changing? If you can answer YES to either of these questions, then you are dealing with an injury or infection.

You should always take notice when you observe something new on your turtle’s shell. If it wasn’t there before – why is it there now? If a sore looks very angry and red, or is bleeding, it may be a fresh injury. At this point, I would recommend reading the Turtle Injuries or Bites article in the First Aid section of this website.

On the other hand, if the sore is round, and white or mushy, this is very much indicative of Shell Rot. Holes and pits are also a sign of Shell Rot and require immediate attention.

When dealing with a newly acquired or rescued turtle, you obviously can’t tell whether the issue is new! In this case, keep an eye on it and take daily photos to monitor it. If it’s changing over the course of a few days or a week, it is an infection.

How to treat shell sores and holes

Whenever you see something pink or red on your turtle’s shell, it’s time to either provide first aid or call a vet. If it is also bleeding, you are dealing with a minor injury.

If you’re certain that the sore is just a small injury, like those caused by rubbing on something sharp, you can follow these steps:

  1. Remove the turtle from the water
  2. Clean the wound and apply povidone iodine or silver sulfadiazine to the affected area.
  3. Place the turtle in a box with some slightly damp paper towels. Keep it somewhere warm. If it is a pet turtle, keep it at about 5F (3C) warmer than the ambient temperature in its enclosure.
  4. Return your pet to its water for a couple of hours a day until healing begins. You will see the sore change, but it may take a few days.

Conversely, if a sore or hole goes all the way through the shell – this is a major injury that requires immediate veterinary care. You can follow steps 1 through 3 while waiting for an appointment but do not let the turtle go back into its water at any point.

For all other sores or holes, it’s important to realise that you are likely dealing with Shell Rot. For starters, it’s a good idea to read this website’s Shell Rot article, which you can find here: How to prevent and treat Shell Rot.

Shell Rot is an annoyingly common disease that is usually linked to poor husbandry conditions. It has a range of symptoms, with the most common being the following:

  • Pits
  • Holes
  • Grey, white, or (less often) red spots
  • Mushy patches
  • Dents
  • Flaking patches of scutes – almost like puff pastry

When to see a vet

If you think the sore, hole, or spot on your turtle’s shell is something new, or getting worse – it’s time to consider seeing a vet.

Obviously, it can be hard to figure this out, especially for new keepers. Don’t underestimate the usefulness of keeping a daily photo diary of the lesions. This is the easiest way to determine if something is indeed growing. That said, if the sores/holes start to multiply then you have a definite answer: something is going on.

The most likely scenario is that your turtle has Shell Rot, be it in a bacterial or fungal form. Reptile vets can treat this condition quite easily at most stages.

In its initial stages, you can even treat shell rot at home using the steps outlined in the Shell Rot article I mention earlier. By reading this article, you will also learn how to distinguish between early and severe Shell Rot, the latter being the stage that requires immediate veterinary treatment.


Amongst all turtle species commonly kept as pets, most shell problems come from two causes: poor enclosure safety and poor husbandry.

Injuries large and small that result in holes, scrapes and cuts are almost always due to poor enclosure safety. Turtles are active foragers and hunters that love to be doing something. Sometimes that can entail looking for food, whilst others it can entail chasing each other, fighting, or trying to escape.

During these activities, if there’s a sharp object or ornament in the enclosure, they will eventually hurt themselves on it. Preventing this is as simple as checking every piece of furniture in their home and making sure it is smooth.

For highly aquatic species, it’s also important to also make sure that the depth of their water is at least twice the length of their carapace. This helps avoid injuries from diving in and hitting the bottom. Use this measurement again for the height of the sides of the enclosure to prevent escapes and falls.

When it comes to sores caused by infections, good husbandry is the only real prevention. one measure that goes a long way to preventing Shell Rot, for example, is to make sure that your turtle has a dry basking spot. Completely dry.

Some highly aquatic turtles may spend most of their waking hours in the water and sleep there at night. But even these species need to be able to dry out completely at least once a day. This is simply how their skin and shell have evolved. If they can never dry out, Shell Rot will eventually set in.

Another key factor is hygiene. Maintaining good enclosure hygiene and using a good water pump and filter can give your turtle’s immune system a huge boost. In fact, regular filter changes and enclosure cleaning can stop germs from building up in high enough numbers to attack your pet in the first place.

Finally, always research your turtle species and make sure you get their enclosure temperatures correct. Their bodies, and therefore immune systems – have specific temperatures that they function best at.

Wrapping up

Shell sores and holes have a variety of causes. Occasionally a hole can be from an old injury, or even something done intentionally by a human. Often, however, a shell sore or hole is from a fresh injury or infection.

As I mention earlier, if there is a new hole – or anything else – in your turtle’s shell you need to investigate and decide whether to see a vet.

Generally, Shell Rot is your most likely culprit. You should be particularly suspicious if you see several holes – almost like pits – next to each other, or if a sore is growing in diameter.

As the owner, it’s up to you to do as much research as you can and use information from this site to get it under control, with or without the help of a vet.

Sometimes you can indeed reverse Shell Rot or provide adequate first aid for minor injuries. If you think you could be dealing with an advanced infection or major injury, however, I recommend going straight to a vet.

What Next? Well… Check out the links below!

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