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How to Spot Turtle & Tortoise Mouth Rot

Mouth rot in turtles and tortoises is a serious but treatable disease and occurs in all species. It is in fact one of the most common diseases in captive and wild chelonians alike.

As well as mouth rot, you may see it referred to as necrotic stomatitis or necrotizing stomatitis. Don’t worry about which term is best – they all refer to the same thing: an infection of the mouth.

As with shell rot, there is a widespread misconception that mouth rot is always a bacterial infection. Though bacteria are involved in most cases of mouth rot in captive animals, viruses are occasionally responsible too.

That said, the true cause of mouth rot is seldom the germs themselves. The real culprit is usually a husbandry mistake which allowed the infection to take hold.

Whatever the case, we need to understand this condition to fight it – so in this article we’re going to discuss how to spot mouth rot, how to treat, prevent it, and when to see a vet.

Tortoise Mouth rot

How to spot mouth rot

Greek tortoise with mouth rot positively diagnosed with herps virus
Greek tortoise with mouth rot positively diagnosed with herps virus

Ok, I admit it – this is a tough one! To identify mouth rot, we need to be aware of both physical and behavioural symptoms.

As I’m sure you are aware, getting a reptile to open its mouth can be tricky. My recommendation is that you never try to force your pet to open its mouth, as this can do more harm than good! Minor scrapes to the soft tissue can make an infection worse or start a new one.

If you wish to check the inside of your pet’s mouth, then your best bet is to sneak a peek when it is feeding (if it is still feeding!). Otherwise, animals with mouth rot will often keep their mouth open to try to get more comfortable – this provides another opportunity to take a glance.

Generally, the first sign that mouth rot is present is lack of appetite. This is your biggest behavioural symptom because an animal with this disease will eat less or stop all together. Sudden lack of appetite can also be a sign of a respiratory infection, so you must take it seriously either way. 

Other behavioural symptoms include:

  • Lethargy (sluggishness)
  • Signs of stress such as restlessness or constantly hiding
  • Sudden lack of fear

The animal may also show the following physical symptoms:

  • 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

As always, you know your animal best. A change in behaviour is always a cause for concern – and if that change is sudden lack of appetite then you should suspect mouth rot as a possible cause. 

How to treat it and when to see a vet

As soon as you spot any of the symptoms I mention above, it’s time to contact a vet. Some conditions can be treated at home with the help of online sources, but mouth rot isn’t one of them.

Furthermore, when mouth rot gets to an advanced stage, it can flip from an easily treatable condition to a dangerous one.

Mouth rot in early stages

For mouth rot in its early stages, your vet will examine the animal (with or without sedation) and prescribe topical antiseptic such as Betadine for you to swab around your pet’s mouth once or twice a day for a few weeks.

Though this course of treatment sounds easy, it is still important to get the help of a vet as they will choose the best antiseptic and tell you how to use it (Betadine, for example, needs diluting to the correct concentration). Your vet may also prescribe antibiotics to make sure that the infection disappears completely.

Serious cases of mouth rot

For serious cases of mouth rot, treatment will be more intense and possibly involve a stay at the vets. Severe infections may pass through the mucus membranes and tongue before attacking the bones underneath.

If your vet suspects that the disease is this advanced, they will sedate the animal and do a thorough examination, at which point a tissue sample or swab may be taken for testing.

If tissue damage is found, debridement will be undertaken. Debridement is the surgical removal of dead tissue and is necessary to allow healing to begin.

In cases with severe tissue damage, euthanasia may be the only solution. Generally, however, you will have noticed a problem and taken your animal for treatment well before this “point of no return”.

After these steps have been taken, antibiotics will be prescribed, and possibly an antifungal medication or antiseptic.

Though the antibiotics will kill any bacteria involved, an antifungal medication or antiseptic may be prescribed because mycoses (fungal infections) often set in where bacteria have already started an infection. 

Finally, your vet will either give you detailed instructions for helping your turtle recover at home or keep them at the practice for a time. 

Exotics vets see a lot of cases of bacterial mouth rot – and know how to treat it successfully. Our role is to either get the animal to them in time or prevent the disease in the first place.

How to prevent mouth rot 

Alligator snapping turtle with healthy mouth open underwater
Alligator snapping turtle with healthy mouth open underwater

Broadly speaking, mouth rot involves three root causes:

  • Poor husbandry – leading to bacterial infection
  • Injuries – leading to bacterial infection
  • Poor quarantine measures – leading to a viral infection

Poor husbandry

In my opinion, a vast majority of mouth rot cases are due to husbandry, making it essential to carry out thorough research on your pet species’ requirements!

Poor husbandry is a big subject, so let’s break it down into the issues that most often cause mouth rot…

Temperature: If a reptile is kept at an incorrect temperature, it weakens its immune system, making it prone to infections. Remember, not all chelonians like it hot like the Desert Tortoise (Gopherus agassizii), some like it much cooler.

One example is the Burmese Forest Tortoise (Manouria emys), which will get ill if kept at temperatures above 75-77F (24-25C). Make sure you get your temperatures right for your pet’s enclosure and this will go a long way to preventing infections.

Vitamin A deficiency: Vitamin A helps maintain the health of the mucus membranes that line a turtle’s mouth. When this barrier breaks down it allows bacteria to infect the tissues underneath.

Vitamin A deficiency is a common cause of mouth rot. Prevention involves researching your turtle’s diet to make it as balanced and healthy as possible.

Hygiene: When hygiene is poor it allows bacteria and other germs to flourish. A healthy animal’s immune system can deal with lower numbers of germs but will become overwhelmed by the high numbers found in a dirty enclosure.

Remove uneaten food immediately and clean the enclosure regularly. For aquatic turtles, take measures to maintain water hygiene, such as UV sterilising filters or water treatments that introduce beneficial bacteria instead.

Jaw position/beak maintenance: This is a leading cause of mouth rot. When a chelonian’s beak grows too long, it can hold the jaw in an unnatural position which allows food to collect in the mouth.

This food then rots and causes infections. Put a cuttle bone in your pet’s enclosure for it to nibble at (you can even let one float in the water); this will help wear the beak naturally. If a beak looks overgrown, take the animal to a vet for it to be trimmed.


Common culprits are sharp bits of gravel and thorns. Some turtles and tortoises simply try to eat everything – there’s no stopping them!

You may find that you must use only large, flat rocks in your turtle’s tank or check every inch of your outdoor tortoise’s enclosure for bramble growth and hazards at least once a week.

Quarantine measures

Time to bust the biggest myth surrounding mouth rot: it isn’t always bacterial!

There are several viruses that infect chelonians and give them mouth rot. Ranaviruses are passed from frogs and fish to chelonians and appear to be linked to deaths in both wild and captive animals.

One American study found that Ranaviruses were responsible for infecting Eastern Box Turtles (Terrapene c. carolina), a Florida box turtle (Terrapene c. bauri), Burmese Star Tortoises (Geochelone platynota) and a Gopher Tortoise (Gopherus polyphemus)

Perhaps as common are chelonid herpesviruses. These can be passed between turtle species & Tortoise Species, each having its own type that it is (probably) more resistant to.

Their telltale symptom is a white plaque that covers the whole of the mouth. In another study, scientists found a whole new species of herpesvirus unique to the Eastern Box Turtle (Terrapene c. carolina) and named it Terrapene herpesvirus 1.

So, what does this tell us? It tells us that turtles and tortoises can, in theory, catch viral mouth rot from contact with wild chelonians, amphibians or fish – and potentially other species of captive chelonian.

This is where quarantine measures come into play. I recommend that you do not mix species unless they naturally occur together. I also recommend keeping new pets in a separate room or location for at least a month before putting them anywhere near your other animals.

Wash your hands after touching them and make sure that you don’t mix feeding bowls or utensils!

Medication for viral mouth rot is experimental at best – but it is much less common in captive animals. Though it’s unlikely you will encounter this type of mouth rot, it is important to know about it all the same.

Wrapping up

Mouth rot sounds bad – but it’s highly treatable. The main thing is to spot it as soon as possible and get help from a vet. This is another condition that exotics vets deal with all the time, but for which home treatment usually isn’t good enough.

When it comes to prevention, your focus should be on husbandry issues and enclosure safety. A healthy animal with a varied diet, correct temperatures and UVB light exposure is much less likely to get mouth rot – even following an injury.

Hopefully, this article has given you the tools to prevent mouth rot or recognize it in time to get appropriate treatment. It should also have helped you understand the importance of quarantine measures.

As always, feel free to get in touch for more help or advice.

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