No matter how hard we try to keep them happy and safe, turtles and tortoises do occasionally get sick. As animal parents it’s our job to figure out why, and what to do next. With turtles this can be a tricky process because their symptoms can be tough to understand. Fortunately, All Turtles is here to help!
Most turtle diseases can be divided into three categories: nutritional, infectious, and parasitic. Some of these illnesses can trigger the others, and some do share symptoms. Generally, however, each illness has some specific symptoms. These are important to observe and record to make diagnosis faster and easier for your vet. Taking photos or notes of anything unusual is always a good idea.
Some of the diseases described in this article can be helped or prevented with good husbandry, but most of the rest are still treatable at the vets, so don’t panic! Let’s go over the most common turtle illnesses and their symptoms.
How to know if your turtle is sick
The first thing to know is that what you’re looking for is a change. After all, a disease is harmful because it causes a change to how an organism functions, whatever its cause may be. Changes in functioning result in changes to appearance or behaviour – and these are what you will notice.
For example, a new spot on your turtle’s shell is a change to appearance, whereas suddenly losing appetite is a change in behaviour. Other changes could be your pet no longer diving into the water when you enter the room, no longer swimming or becoming constipated. Any of these changes need further investigation and are in fact some of the most common symptoms of turtle diseases.
To notice changes, it’s important to get to know your pet’s appearance and habits. Make mental notes (or written if you wish) of what is normal for them. Spending time observing your pet, to the point where you know its behaviour by heart, goes a long way to quickly spotting any problems.
Alongside your observations, it’s important to do regular, visual health checks. Once every week or so, pick up your turtle and look over its shell and skin for spots or lesions. Turn it up slightly so that you can also see its plastron (bottom of the shell). At the same time, listen to its breathing for any wheezing.
Now that we’ve discussed how to keep an eye on a healthy turtle, let’s look at the three categories of turtle diseases and the symptoms for each one.
1. Nutritional diseases in turtles
Nutritional diseases are those that are brought about by an imbalanced diet or lack of UV light. They make up a significant percentage of illnesses in captive turtles but are almost always preventable by researching an animal’s husbandry requirements.
The most common nutritional diseases are metabolic bone disease, vitamin A deficiency, excessive protein intake, and constipation. Of these, mild constipation is the easiest to deal with and can usually be treated at home. The rest can be effectively treated by a vet.
2. Metabolic Bone Disease
This condition is caused by either a dietary imbalance between phosphorous and calcium, a Vitamin D deficiency, or a calcium deficiency (it’s essentially the same as Rickets). Very occasionally, persistent low temperatures can also cause MBD as they harm a turtle’s ability to absorb calcium. Whatever the cause, the result is the same: the turtles body runs out of calcium. When this happens, it strips it from the skeleton and the result is deformity.
Generally, the most common cause of MBD in turtles is lack of UV lighting. Turtles use UV light to synthesis vitamin D, which they in turn use to metabolise calcium. It seems that although they get some vitamin D from food, they’re a lot better at getting it this way.
High levels of phosphorous also cause malabsorption of calcium, as do oxalate rich foods. That said, the ideal phosphorous to calcium ratio for turtles is still hotly debated. Rather than delving too deeply into the science behind it, your best bet is to provide your pet with the healthiest, most varied, and natural diet you possibly can. Do your research and take advice from people who’ve been keeping your species for a good 10+ years.
In a nutshell: insufficient UV light or dietary imbalance = no Vitamin D or no calcium, and this leads to Metabolic Bone Disease.
Metabolic Bone Disease Symptoms
Early MBD symptoms can be general, and include a lack of appetite, lethargy, slight softening of the shell, and swollen legs.
Advanced MBD symptoms are more serious, and include:
- A swollen, deformed jaw that looks almost comical
- Changes to the appearance of the legs
- Changes to the appearance of the shell
- Jerking or twitching movements
- Severe softening of the carapace and plastron – a turtle over a year in age should have a hard shell
- Complete inability to move
When to See a Vet
As soon as you notice a change to the appearance of your turtle’s jaw or legs, or a change to the hardness of their shell. If you have photos of your pet’s old appearance, show these to your veterinarian.
Check our metabolic bone disease in turtles article for more.
3. Vitamin A Deficiency
Vitamin A is the term used for a group of organic compounds that are essential to turtles. These can include different types of retinoids, which are pre-formed types of Vitamin A, and provitamin A carotenoids, which can be used by the turtle to synthesize its own Vitamin A.
This may sound complicated, but whichever type of Vitamin A your turtle needs can be provided by giving them a balanced diet that suits their species.
If enough Vitamin A is not provided, then the result is a deficiency, also known as Avitaminosis A. See the article Turtle Swollen Eyes and Vitamin A deficiencies for an in depth explanation of the issue.
Vitamin A Deficiency Symptoms
- Swollen eyes, sometimes with pus
- Respiratory infection, usually with wheezing, sneezing, gasping and lop-sided swimming
- Lethargy (sluggishness)
- Unexplained weight loss or stunted growth
- Anorexia (refusal to eat)
- Aural (ear) abscesses which look like swellings behind the head
- Mouth rot
- Skin infections (red or white patches)
When to See a Vet
Swollen eyes are the most common symptom – but if you spot any of the above, see a vet immediately.
4. Excessive Protein Intake In Turtles
Like carbohydrates and fat, protein is a macronutrient that forms a major component of most turtle diets. The problem is that if given in excess, it can cause problems in omnivorous species, mainly due to the fact it can cause the shell to grow abnormally.
This abnormal shell growth is referred to as “pyramiding” and is the most obvious symptom of excessive protein intake. There is always debate about the exact protein requirements for each species, but in general no more than 60% of a juvenile or 40% of an adult omnivorous turtle’s diet should be protein-dense foods.
Excessive Protein Intake Symptoms
- Carapace becoming very bumpy and lumpy
- Noticeable thickening of the shell
- Edges of the carapace curling upwards
- A lot of white urates being passed in poop, as solids or liquid
When to See a Vet
Pyramiding can go on for some time before making your pet act “sick”. In fact, the animal may carry on feeding and behaving normally. This is misleading though as the condition can affect growth and health in the long-term. It can also mask other conditions. See a vet as soon as you notice a change to shell appearance.
See our pyramiding article for more.
5. Constipation
This condition is much more common in terrestrial and semi-terrestrial turtles such as the American Box Turtles (Terrapene spp.) and the Asian Box Turtles (Cuora spp.).
Unlike some of the other conditions listed here, constipation is stubbornly common in pets that are otherwise completely healthy!
This makes determining the cause quite difficult, but often it is dehydration. For more information, check out the Turtle Poop and Turtle Prolapse articles.
Constipation symptoms
- For a juvenile under 4 inches (10cm), no poop for more than two days
- For an adult, no poop for more than a week
When to See a Vet
If you’ve tried the measures in the articles I’ve mentioned without success, then you need to book an appointment.
6. Infectious diseases in turtles
Diseases in this category can be caused by a variety of pathogens, with bacteria and fungi being the most common. Though rarely mentioned, viruses also cause disease in wild turtles, and sometimes infect captives if strict hygiene and quarantine measures aren’t observed.
The good news here is that most infectious diseases can be prevented with good husbandry: epidemics are rare amongst pets. If your pet does catch something, it’s important to find the route cause, and always check their temperatures as your first step.
The most common infectious diseases of turtles are Respiratory Infections (R.I.s), Shell Rot (aka Ulcerative Shell Disease), Mouth Rot (aka Necrotic Stomatitis), and Skin Infections. Any of these infections can cause death and must be caught early. Respiratory Infections and Mouth Rot should be considered an emergency.
7. Respiratory Infections
These infections can affect the upper respiratory tract, in which case they may be referred to as URTDs, or the lungs, in which case they are known as pneumonia. RI’s are particularly common in animals who have been exposed to low temperatures, poor hygiene, or a diet lacking in Vitamin A. You can read more about them here: Turtle Respiratory Infections.
Respiratory Infection Symptoms
For an URTD:
- Loss of appetite
- Mucus coming from the mouth, nose, or eyes – sometimes making bubbles
- Epiphora (excessive watering of the eyes)
- Lethargy (sluggishness)
- Wheezing
- Open mouth breathing and stretching the neck out for no apparent reason
- Limp behaviour when basking
For Pneumonia:
- Loss of appetite
- Lethargy
- Lop-side swimming or inability to dive (due to fluid on the lungs, causing buoyancy issues)
- Wheezing
- Open mouth breathing and stretching the neck out for no apparent reason
- Terrestrial turtles walking in circles (less common).
- Pink areas of skin on the underside of legs and near bridge (part of the shell that connects the top to the bottom).
When to See a Vet
If you see any of the symptoms listed above, contact a vet. Often, several of these symptoms may be absent, and the first is usually lack of appetite.
For pneumonia, the only two symptoms may be lack of appetite and lop-sided swimming. This last symptom means that urgent treatment is required – make sure you mention it to your vet when booking an appointment.
8. Shell Rot
Shell Rot is a common disease in turtles, and usually stems from an injury to the shell or poor hygiene. It can be either slow and creeping, as is often the case with fungal shell rot, or aggressive, as is the case with certain bacterial types.
Whichever the type of Shell Rot present, changes to the appearance of the shell are always the first tell-tale symptom.
A common source of confusion is the difference between scute shedding and shell rot symptoms – I would advise reading the full Shell Rot article to gain an understanding of this.
Shell Rot Symptoms
- In the early stages: white or discoloured patches on the shell. Flaking may also be present.
- In later stages: dents, pits, mushy areas, and bright red ulcers. Severe flaking may or may not be present.
When to See a Vet
Shell Rot can be hard to correctly diagnose and treat. If you suspect a case in its early stages, using the measures outlined in the Shell Rot article can help. Be sure to keep a photo of log of progress. If no improvement is seen after two to three weeks, then a vet should be consulted.
If you suspect severe shell rot, a vet should be consulted immediately, as septicaemia (a blood infection) could set in.
Sometimes, hard water deposits can look a lot like shell rot but are a lighter colour. For more information on this, check out the White Spots on a Turtle’s Shell article.
9. Mouth Rot
Like shell rot, mouth rot can be caused by a variety of germs, but its root cause is usually an injury, poor hygiene, or imbalanced diet. Overall, Vitamin A deficiency or poor temperatures are perhaps the most common causes, but beak overgrowth can also be a factor.
Because turtle beaks grow over time, they need to be given a diet that naturally wears them down to a safe length. Beak overgrowth leads to bad jaw position, which in turn leads to food and germs building up and causing infection. Always research your turtle species’ diet and try floating a cuttle bone in their water for them to chew on.
You can find out more about prevention in the Turtle and Tortoise Mouth Rot article.
Mouth Rot Symptoms
- Lethargy (sluggishness)
- Signs of stress such as restlessness or constantly hiding
- Sudden lack of fear
- Drooling
- Keeping the mouth open constantly
- Cheesy plaques and red specks in mouth
- A white plaque covering the whole of the inside of the mouth (usually a sign of herpesvirus infection)
- A bright red mouth or area in the mouth
When to See a Vet
Mouth rot can advance extremely quickly, and I always recommend seeing a vet immediately. Don’t be drawn in by some resources that tell you to treat it home – it’s not worth the risk!
10. Skin Infections
The causes, symptoms and treatment of skin infections are all remarkably similar to shell rot. The major difference of course being that symptoms appear on the skin rather than the shell!
Skin Infection Symptoms
- Lack of appetite and general lethargy
- Red, white, or grey patches or circles on the skin
- Thick skin shedding that leaves red areas underneath
When to See a Vet
Read the White Spots on a Turtle’s Shell article, as this also includes information on how to tell the difference between normal skin shedding and infections. If after reading you feel that your turtle is shedding in an unusual way, or if it has any red/sore patches on the neck or legs, contact a vet.
11. Parasitic diseases in turtles
By far the most common parasites in turtles are intestinal worms, which you may also hear referred to as endohelminths. These are rarely dangerous and respond well to treatment ifthe correct choice of drug is used.
Other intestinal parasites include various species of Protozoa, which can cause amebiasis and other dysentery-type diseases. Overall, Protozoan infections are more serious and require urgent veterinary diagnosis. Fortunately, they are almost all preventable with solid hygiene and quarantine measures.
If you suspect worms or a Protozoan infection, I suggest reading the Turtle Poop article.
Turtles don’t tend to suffer mite or tick infestations due to the fact they spend so much time in water which would drown them. The only ectoparasites you may notice are the occasional leech or two on turtles that live in an outdoor pond. Fortunately, these can be gently removed and almost never do lasting damage.
The most common parasitic infections in turtles are Roundworms (Ascarids), Hookworms, Pinworms, and Protozoa.
Parasitic Disease Symptoms
- For Roundworms: mild diarrhoea, lethargy, appetite, or weight loss. These worms may be visible in stools and will look like white string or spaghetti.
- For Hookworms: diarrhoea, bloody stools, appetite, and weight loss. Hookworms are invisible to the naked eye.
- For Pinworms: light diarrhoea, weight loss, or no symptoms whatsoever. Pinworms are also invisible to the naked eye.
- For Protozoa: severe diarrhoea and lethargy. Protozoa can only be seen under a microscope.
When to See a Vet
I’ve grouped these diseases together because of how similar they are. As you can tell, they share common symptoms, and unless you see worms in your turtle’s poop it is extremely difficult to tell them apart.
This means that the analysis of faecal or blood samples is essential for diagnosis.
If your pet is suffering from persistent diarrhoea, or you think you can see worms in its stools, then it’s time to see a vet. Try your best to take the turtle’s most recent poop with you to the appointment – this sounds gross, but it can make the vet’s job a whole lot easier.
Wrapping Up
Turtle diseases come in many different forms. Some have specific symptoms, while others are much harder to diagnose. Overall, the best way to tell if you turtle is sick is by looking for a change in either their appearance or behaviour. This is your cue to take a closer look!
Once you suspect something is up, it’s time to be proactive and observant. By checking through the diseases on this list and looking out for their symptoms you can take notes that will make it easier for your veterinarian to diagnosis your pet.
Faster diagnosis leads to faster, more accurate treatment and increased chances of success.
As always, its important to remember the role hygiene, temperature, and diet play in preventing illness. If your turtle gets sick and recovers, consult your vet and this website for information on improving your husbandry.