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This book is packed with easy-to-understand information on selecting and setting up a habitat, feeding, breeding, and all other aspects of proper leopard gecko care.

Leopard Gecko Mouth Rot 101: Causes & Treatment

Also commonly known as infectious stomatitis, mouth rot is a painful and often severe bacterial infection of the mouth. 

If your gecko’s mouth is red, oozing, or swollen, mouth rot is the likely culprit. 

But what causes this illness, and how do you treat it?

Mouth rot is most often caused by stress weakening your gecko’s immune system, resulting in them becoming more prone to bacterial infections. It causes your gecko’s gums and mouth to become red and swollen and often spread to other parts of the body if left untreated.

To learn more about mouth rot in leopard geckos, keep reading. 

We’ll cover everything you need to know to keep your gecko’s dental health in great condition and what to do if you suspect your pet has this particular bacterial infection.

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What Is Leopard Gecko Mouth Rot?

“Mouth rot” is a more casual term for what is medically known as infectious stomatitis. 

It is a painful bacterial infection which primarily affects your gecko’s mouth, teeth, and gums, though it has been known to spread throughout the body if left untreated. 

Although it is normal for your gecko to have a small number of certain bacteria within its mouth and body, infectious stomatitis is particularly problematic as it overwhelms geckos with weak immune systems.

Normally, your gecko’s immune and oral health will be resistant to bacterial infections with a healthy diet and ideal enclosure conditions. 

However, if the lizard becomes stressed due to certain environmental conditions, improper handling, cohabitation with other geckos, or other unusual factors, the stress will weaken their immune system.

As a result of their weakened immune system, the gecko will become more susceptible to infections, and the fragile balance of bacteria in their body will become unbalanced. 

This leaves them especially prone to mouth rot.

What Causes Leopard Gecko Mouth Rot?

Infectious stomatitis is primarily caused by severe and prolonged stress to your leopard gecko. 

Stress will, over time, cause your pet’s immune system to become weaker and less able to fight off infections. 

Mouth rot is one of the most common infections caused by stress. 

Typically, your gecko’s mouth has a delicate balance of a small, healthy amount of bacteria inside it. 

However, once their immune system becomes weakened, this balance becomes offset, allowing the bacteria to rapidly multiply and overwhelm your gecko.

Many environmental factors will stress out your gecko and leave their immune systems weaker over time. 

Some of the most common potential stressors associated with mouth rot include:

  • Improper temperature or humidity settings in the gecko’s enclosure
  • Improper cohabitation with other geckos
  • Poor or rough handling
  • Prolonged hunger or thirst/poor diet
  • Loud or chaotic environment around the enclosure

Next, we’ll cover each of these stressors and how to keep them to a minimum, so your gecko’s immune system is strong enough to fight off mouth rot in the future.

Causes: Improper Temperature/Humidity

Your gecko’s enclosure has very specific settings you’ll need to maintain at all times when it comes to temperature and humidity. 

Since leopard geckos are ectotherms, their bodies rely on their environment to stay warm and comfortable.

Leopard geckos are native to dry, arid areas in the Middle East, so you’ll need to replicate these environmental conditions as closely as possible. 

The enclosure in which you house your gecko will need a basking area or a hot side, and a cool side on the opposite end, with a gentle temperature gradient in between.

The basking area of your gecko’s enclosure, or the space directly underneath their basking bulb, will need to be within 90 to 95° degrees Fahrenheit (35° C), while the rest of the warm side should be around 80 to 85° degrees Fahrenheit (29° C) or so. 

The cool side of the enclosure should be within 75 to 80° degrees Fahrenheit (27° C), and the tank should get no cooler than 70° degrees Fahrenheit (21° C) at night.

The enclosure will need to be kept within 30 to 40% humidity as far as humidity goes.

If you’re worried your gecko’s enclosure is too cold at night, invest in a ceramic heating element. 

These heating elements give off warmth your gecko needs, yet they won’t disturb their sleep cycles with harsh lighting.

Causes: Improper Cohabitation

Cohabitating multiple leopard geckos is tricky and generally not recommended unless you are very experienced with caring for these reptiles.

If you are cohabitating your geckos, be sure to never put two males together, as they are very territorial and will fight, in turn causing stress to all the geckos in the enclosure. 

It is possible to house a male and female breeding pair together, but you’ll need to monitor their activity closely for any signs of distress or fights. 

Female geckos are also commonly housed in pairs or groups, though this is also tricky to maintain, as they will still sometimes fight over resources like food, water, and basking spots.

Cohabitated geckos will often result in them forming a hierarchy within their group, meaning there will inevitably be one gecko who is larger and more dominant than the others. 

This is problematic for the above reasons and very stressful to the smaller gecko or geckos in the enclosure.

Cohabitation stress is a common factor contributing to infections like mouth rot, so house your geckos separately whenever possible.

For more details, check out our guide to leopard gecko cohabitation.

Causes: Poor or Rough Handling

Leopard geckos are sensitive and fragile creatures, meaning you’ll need to handle them with extreme care. 

They are also fairly skittish and jumpy when being handled, meaning they are prone to falls, which often cause stress injuries.

If you need to pick up your leopard gecko, be sure to always approach them very slowly and from the side rather than from above to avoid frightening them. 

Support their entire body and tail with your hands and do not squeeze, shake, or otherwise handle them roughly.

Handling your gecko improperly regularly will be very stressful and upsetting to your gecko, resulting in a weakened immune system. Avoid handling them excessively.

Causes: Poor Diet

Your gecko’s diet is an important factor in keeping them healthy and happy and preventing illnesses like mouth rot. 

Leopard geckos are purely insectivorous, meaning they strictly eat insects. 

You’ll need to feed your gecko a variety of insects and supply them with a calcium supplement to ensure they get the vitamins and nutrients they need to thrive.

Don’t just pick one type of bug and stick to it; providing plenty of dietary variation is key to a happy lizard. 

You have plenty of great choices commonly found at pet shops or online retailers, from crickets to Dubia roaches and mealworms.

Additionally, be sure your gecko is eating enough and is not overweight. 

Monitor their growth alongside a leopard gecko growth chart, or ask your vet if your pet is within a healthy weight, as underweight or overweight lizards are prone to stress and weakened immune systems.

Causes: Loud/Chaotic Environment

Another factor often overlooked by many reptile owners is the environment where you keep your gecko’s enclosure. 

Is your lizard’s enclosure kept in a room by themselves, or are they surrounded by other pets or children in the home? 

Is the room particularly loud, bright, or otherwise chaotic? 

If so, you might want to move the tank to a quieter, calmer location, as too many stressful external stimuli will quickly stress out and upset your gecko. 

If they are exposed to a stressful environment for a prolonged period, their immune system will weaken and leave them prone to developing infections like mouth rot and other painful illnesses.

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Symptoms Of Mouth Rot In Leopard Gecko

So, now you understand the main causes which contribute to mouth rot in leopard geckos. 

But what if you suspect your gecko already has this illness? 

Let’s break down some symptoms to look for when determining if your pet has developed infectious stomatitis.

The main signs to look for include:

  • Loss of appetite
  • Pus coming from the mouth
  • Redness or swelling around the mouth and jaw
  • Dead or flaky tissue coming from the mouth
  • Fatigue and irritability

If you notice any of these symptoms, be sure to get your pet to a qualified reptile vet as soon as possible to get an official diagnosis and antibiotic treatment moving forward.

Symptoms: Loss of Appetite

Perhaps one of the most obvious signs of mouth rot in leopard geckos is a significant loss of appetite. 

Since this infection primarily affects the inside of the mouth, it makes sense your pet will be unwilling to eat if they are suffering from it.

If your gecko hasn’t been eating as much as it normally would, take a closer look at their mouth to determine if they are displaying some of the other common symptoms associated with mouth rot.

Symptoms: Pus Coming from the Mouth

If you notice any clear, yellow, green, or brown pus oozing from your gecko’s mouth, this is a clear sign of infectious stomatitis. 

Clean the pus with a clean, warm, damp rag, and use an antiseptic as recommended by your veterinarian.

Symptoms: Redness/Swelling Around the Jaw

Another clear sign of infectious stomatitis in leopard geckos is redness and swelling of the mouth and jaw area.

Be very careful not to handle your gecko roughly if you notice this symptom, as it is very painful and stressful for them.

Symptoms: Dead/Flaky Tissue Around the Mouth

If your gecko is developing mouth rot, you’ll likely also notice flaky, dead tissue coming from their mouth and jaw. 

This tissue will often be red or discolored and have an unusual odor similar to the pus coming from their mouth.

Clean the area carefully with warm water and an antiseptic as recommended by your vet, and avoid handling your gecko unless necessary for treatment to avoid stressing them out further.

Symptoms: Fatigue and Irritability

It’s only natural for your gecko to be in a pretty foul mood if they’re suffering from infectious stomatitis. 

Be sure to avoid handling them excessively and keep any external environmental stressors to a minimum while treating their infection.

How To Treat Mouth Rot In Leopard Geckos

If you have identified a possible mouth rot infection in your gecko, your first and most important step will be to get them to a reptile vet as soon as possible. 

It is best to avoid attempting to treat the infection on your own until you’ve gotten a diagnosis and advice from your vet. 

You will also need prescription antibiotics, which will be prescribed by your vet to properly treat mouth rot.

You should do some things to help the healing process along, though, such as gently cleaning their mouth and jaw area with cotton swabs and an antiseptic like betadine. 

Be sure to check with your vet first for their recommendation on what type of cleanser to use.

Additionally, if your gecko’s case of mouth rot is particularly severe, they will likely need fluids to stay hydrated and fed, as eating will be difficult for them while they recover. 

In some cases, they will need surgery to remove damaged tissue around the mouth, though this is often avoided by diagnosing the infection and treating it as quickly as possible.

The sooner you get your gecko to a vet, the better. 

Don’t wait for the infection to clear up on its own; in most cases, mouth rot will only worsen until it is treated with the proper antibiotics and antiseptics.

Preventing Mouth Rot In Leopard Geckos

The best way to prevent your pet from developing mouth rot in the future is to practice proper reptile husbandry, avoid unnecessary stressors, and keep their enclosure clean at all times. 

As mentioned above, infectious stomatitis is primarily caused by a weakened immune system due to stress, making the gecko especially prone to bacterial infections. 

If your gecko’s environmental stressors are kept to a minimum, the delicate balance of bacteria in their body will remain undisturbed, and their immune system will be strong, resulting in a happy and healthy lizard.

If you notice any common symptoms like those listed above, immediate treatment is essential to prevent worsening illness and require more intensive treatment like surgery or fluid therapy.

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