Leopard Gecko Mouth Rot (Causes, Symptoms & Treatments)

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You must have heard about mouth rot if you’ve been keeping leopard geckos for a while. But what is this condition?

Mouth rot is a bacterial infection. As its name suggests, it affects your leopard gecko’s mouth, gums, and teeth. However, this infection can spread to other parts of your reptile’s body. It is particularly common among leopard geckos with weak immune systems. 

What is Mouth Rot? 

Medically, mouth rot is referred to as infectious stomatitis. It is a bacterial infection that affects the mouths of reptiles. Apart from leopard geckos, it also affects snakes, turtles, and lizards. Some of the bacteria that are present in the mouths of those with this infection include:

  • Klebsiella pneumoniae
  • Escherichia coli
  • Pseudomonas aeruginosa
  • Morganella morganii 

While these types of bacteria are usually in the mouths of healthy reptiles, they usually overgrow in those with infectious stomatitis. This causes an imbalance and a slew of uncomfortable symptoms. Keep in mind, though – this infection is contagious. As such, it’s important to keep any reptile that has mouth rot separate from other reptiles. However, it can be around you and your other pets – mouth rot can’t be transmitted to birds and mammals. 

Why do leopard geckos get mouth rot? 

The main cause of mouth rot in leopard geckos is a weakened immune system. When your leopard gecko’s immune system is weakened, bacteria can easily overgrow in its mouth and cause mouth rot. 

A weakened immunity also slows down your gecko’s healing abilities, leaving mouth wounds open for longer and putting them at risk for infection. 

For your leopard gecko’s immunity to be this low, it has to be stressed for prolonged periods. Such stress is usually caused by:

1. Improper tank lighting/temperatures/humidity levels

While leopard geckos depend on tank lighting to know when it’s time to sleep, they rely on tank temperatures to heat their bodies and digest food. 

As such, improper tank lighting and temperatures can affect their health and make them more stressed.

Also, improper humidity levels can affect their ability to shed their skin, adding to their stress. To make matters worse, high levels of humidity can contribute to the growth of harmful bacteria. 

2. Poor hygiene

Harmful bacteria thrive in dirty tanks. Leopard geckos living in such tanks are much more stressed and prone to various infections. 

That’s why it’s important to regularly spot clean your leopard gecko tank and do a thorough weekly clean. Beyond that, deep clean the tank after every one or two months. This is particularly important if your leopard gecko already has another disease. 

3. Poor diet

Another thing that can stress out your leopard gecko and compromise their immunity is a poor diet. 

So ensure you feed your gecko once a day or every other day and that you offer nutritious worms. 

While it’s great to count on staples like crickets and mealworms, it’s also important to include worms with higher calcium to phosphorus ratios. 

Beyond this, gut-load the insects and sprinkle some calcium and vitamin powder on them before serving. 

4. Oral injuries 

Apart from stressing your leopard gecko and compromising its immunity, oral injuries are an easy target for infections like mouth rot. As such, it’s important to avoid them at all costs. 

A good place to start is choosing a safe substrate – some substrates cut your gecko’s mouth when it ingests them. That’s why it’s always best to get a substrate that your leopard gecko can’t eat or that can’t affect them if they do.

Another thing you can do to prevent mouth cuts in leopard geckos is to avoid feeding them hard worms or those with mandibles that can harm them. And if you must feed them the latter, crush their heads before offering them up. 

5. Parasites 

Internal parasites can suck all the nutrients you are providing your leopard gecko through its diet. 

Ultimately, this can weaken its immune system and stress it out, putting it at risk for mouth rot. 

If you suspect that this is happening to your gecko take it to the vet to get a fecal egg count (FEC) test and get treated appropriately.

6. Improper handling

Constantly handling your gecko, squeezing it tightly, or grabbing it by the tail can cause undue stress. If this stress is prolonged, it can lower your gecko’s immunity and put them at risk of developing mouth rot. 

7. Noisy environment

Another thing that seriously stresses a leopard gecko is living in a noisy environment. This can even affect their ability to sleep, leaving them fatigued and immunocompromised. That’s why it isn’t advisable to place your leopard gecko’s tank in a room that children and pets frequent. 

8. Cohabitation

Placing your leopard gecko in the same tank as another animal can cause it stress and even harm its health. This situation can not only force your reptile to compete for food and space but also expose them to bullying. 

If things escalate, your leopard gecko can get into fights and get injured, further compromising their immunity. 

To make matters worse, cohabitation also puts your reptile at risk of getting mouth rot from its tankmate. 

Leopard Gecko mouth rot symptoms

Your leopard gecko has mouth rot if it exhibits the following symptoms:

Redness or swelling 

Mouth rot causes inflammation around the mouth and gums. This usually manifests as redness and/or swelling in the area. Some leopard geckos will even have visible wounds in their mouths. 


If you notice that your leopard gecko secretes pus and other foul-smelling fluids from its mouth and nose, it probably has mouth rot – this is a major symptom. 

The pus can be yellow, green, or even brown. You can deal with symptoms by cleaning the area using a clean, warm rag and using a vet-approved antiseptic that your vet approves. 

Bleeding gums

When mouth rot is severe, it can wear out your leopard gecko’s gums and make them bleed. 


An accumulation of yellow plaque on your leopard gecko’s gums and mouth can be an early symptom of mouth rot. Offering your reptile feeder insects with tough exoskeletons can help rub off this plaque.

Lack of appetite

Infectious stomatitis can make eating uncomfortable and even painful for leopard geckos. This can make them refuse food and even water. And in cases where the infection affects only one side of the mouth, your reptile may start using only the unaffected side to eat. 

Dead tissue

Mouth rot can also make your leopard gecko develop layers of dead skin in its mouth. This usually smells terrible and is an indication that it’s time to go see a vet if you haven’t already. 


Leopard geckos can salivate excessively when they have mouth rot. This is because of the pain and discomfort that this infection causes. This situation can even make your leopard gecko sleep with its mouth open, leading to drooling. 

Black teeth

When mouth rot spreads and gets severe, the infection can penetrate your leopard gecko’s teeth and make them rot. In some cases, the teeth can even start falling out. 


Like all infections, mouth rot saps your leopard gecko’s energy, causing fatigue and irritability. 

Does mouth rot go away on its own? 

Mouth rot doesn’t go away on its own. If left untreated, it can spread to other parts of your leopard gecko’s body, such as the eye, lungs, and intestinal tract. Ultimately, this can prove fatal. As such, mouth rot should be treated quickly and aggressively immediately after it’s diagnosed. 

How to Treat Mouth Rot in Leopard Geckos

Vets usually treat mouth rot by thoroughly cleaning your leopard gecko’s mouth and prescribing antibiotics. In some severe cases, they may choose to operate on your leopard gecko. After the surgery, your vet will recommend supportive care like heat application or injection of supplements into feeder insects. 

Beyond this, your vet will strive to find out the root cause of the mouth rot and deal with it, even if it’s another disease. This is because mouth rot is usually a sign that something else has been wrong for a while. 

However, before any treatments are implemented, your vet will first confirm that your leopard gecko actually has mouth rot. 

They will do their diagnosis by physically checking for symptoms, testing cultures of mucus/discharge, and conducting a complete blood count (CBC) test. 

The vet will also ask about your leopard gecko’s medical history if things are unclear. If they are worried that your pet has underlying cancer, they will also take a biopsy.  

Final thoughts 

Because of how bad mouth rot can get and how hard it can be to diagnose in the early stages, preventing it is always better than curing it. 

Fortunately, you can prevent it by providing your leopard gecko with a balanced diet and ensuring that its environment is free of stressors – things you should be doing anyway. 

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