• 1

Mouth rot, or stomatitis, is a fairly common health problem in captive reptiles, especially snakes. It is very important that it is recognised and treated early as it can lead to serious, indeed potentially fatal, complications such as lung or generalised infections if allowed to go untreated.

What is It?

Stomatitis means inflammation of the (oral) cavity, i.e. the mouth. Basically the tissues of the mouth (the gums, throat etc.) become inflamed, generally as the result of an infection.

What Causes It?

Stomatitis is generally due to an infection, although there is usually a predisposing cause, such as a wound (see below). There are frequently a variety of different micro-organisms involved and sorting out which is the major one can be difficult.

The majority of cases are considered to be caused by bacteria, often Aeromonas or Pseudomonas species. These bacteria are usually resistant to many antibiotics. Viruses have been implicated in some cases, particularly in Chelonia. Fungi have also been found in affected mouths, but are considered to be secondary invaders in most cases.

It must be remembered, though, that, as is the case with most bacterial infections, a predisposing factor is often necessary to weaken the animal’s defences before bacteria can cause major problems. This is not always the case but frequently is.

In the case of stomatitis, several things have been suggested as predisposing factors. In individual cases, mouth wounds are often found or assumed to be involved, perhaps associated with rough force-feeding or biting something it shouldn’t have (such as the owner’s hand!) which was then pulled away. A common factor in lizards is a damaged snout due to wild escape attempts.

More generally, anything affecting the immune state of the animal will predispose it to infection and the mouth is one area very exposed to environmental contamination by pathogens or potential pathogens. Things such as stress, weakness, malnutrition or poor environmental conditions come under this heading. Low white blood cell counts immediately following hibernation may be a factor in Chelonia. More specifically, it has been suggested that marginal Vitamin C deficiency may be a factor.

What Are The Signs?

The first sign noticed will often be anorexia, perhaps a with weight loss and/or lethargy. By the time this is considered significant, however, the mouth may be fairly badly affected. This is especially true in snakes, where missing the odd meal is not particularly unusual.
By looking in the mouth, signs may be apparent much earlier and it may be that checking in the mouth should be a part of routine examination of your animals, perhaps on a weekly basis.

In the early stages the only noticeable symptom will be an increase in the amount of mucus or saliva in the mouth (deciding on what constitutes an increased amount may only be judged with experience if no other signs are present). Pinpoint red spots (tiny haemorrhages or petechiation) may also be seen and the oral mucosa may be generally reddened and inflamed. This will then progress through areas of reddened ulcers to the worst cases, where the mouth is full of cheesy pus and necrotic debris and may be visibly swollen.

Possible secondary effects include infection and destruction of the jaw bones and teeth (osteomyelitis), blockage of the lacrimal duct, leading to swelling of the subspectacular space (in snakes) or tear overflow and spread of the infection to the trachea and lungs, causing pneumonia. A spread of infection down the intestinal tract is also possible, but does not seem to be a common sequel. Generalized spread of infection, leading to septicemia, can be a rapidly fatal complication.

What Can Be Done About It?

As always, prevention is better than cure. In the case of stomatitis, as in almost all health problems in captive reptiles, maintaining a reasonably clean vivarium and keeping the animal in appropriate housing will generally go a long way towards preventing any problems. Avoiding mouth wounds is, obviously, an important factor which, amongst other things means great care must be taken with force-feeding (if this technique is used at all). Snout-rubbing should be prevented and it may be necessary to install some sort of screen over the glass to stop this.

If a mouth wound should appear, daily, or even twice daily, cleaning with an antiseptic, such as Tamodine wound cleanser, should go a long way to preventing infection taking hold. Gently dabbing it on with a cotton bud is sufficient in most cases.
If, however, you are in any doubt (and certainly if pus is visible in the mouth) a vet should be consulted as antibiotics will usually be necessary. Specific treatment regimes will depend on the state of the animal, the stage of the disease and so on and assessment of the problem may involve further tests / investigations over and above a normal clinical examination. These may include:

1). A swab from the mouth to culture the bacteria involved and assess their sensitivity to antibiotics. This is generally strongly advisable, as the bacteria involved are often resistant to many antibiotics. Treatment with antibiotics will usually be started anyway, but results from the swab can be vital in modifying the drug used to a suitable one.

2). Blood samples to assess how the animal is responding to the infection and the functioning of various organs such as liver and kidney which might be affected by bacterial toxins.

3). Radiography - X-rays may be used to assess involvement of bones in the problem - if the jaw bones are extensively involved, for example, great care will be needed in cleaning the mouth.

These and possibly other tests will be used to determine the appropriate course of action by your vet. Treatments that may be involved include:

1 ). Thorough debriding (scraping away /cleaning) of all lesions (affected areas) in the mouth, followed by application of antiseptic and/or antibiotic preparations. In severe cases, or in the case of dangerous individuals, sedation or general anesthesia may be required for this.

2). This will probably be followed by daily (or more frequent) cleaning of the mouth and application of antiseptic and/or antibiotic preparations.

3). Systemic antibiotic treatment, usually by injection. Once the results of any swab taken come back an appropriate antibiotic can be selected on the basis of these, but this will take a couple of days. Until then an antibiotic will usually be selected according to what has been found generally useful in the past. All vets will probably have their preferred antibiotics for such cases but, on the sensitivity results I get, I find Baytril to be by far the most generally effective drug in such cases.

4). Supportive therapy is usually very important. This involves maintaining the reptile in an appropriate temperature (generally at the preferred body temperature, although with some antibiotics a specific temperature is advised) and humidity. Injectable support such as multivitamins or fluids may be advised. The animal will probably need some form of nutrition, as it will rarely be eating, and this will normally be administered via a stomach tube. During this operation care must be taken to avoid forcing infection down the esophagus and, for this reason, tubing is best carried out just after the mouth has been cleaned and is still full of the antiseptic/antibiotic).


Stomatitis can be a big problem in reptiles and, if not detected early, can be very difficult to eliminate. The possibly fatal complications which may occur make it highly advisable that routine checks are carried out for any signs of the condition developing - a mouth inspection should certainly be part of routine health-monitoring of captive reptiles on a weekly basis. If signs are seen seeking veterinary help for the animal is essential. It is hoped that the above article can help the herpetologist to avoid stomatitis affecting his or her animals or catch any problem early, before it becomes too bad. It also, hopefully, explains some of the approaches the vet might take to the problem.
References/Further Reading
Bone, Robin D (1992) Gastrointestinal Disease. Chapter 10 in Manual of Reptiles. Published B.S.A.V.A.
Cooper, J.E. & Jackson, OF. (1981). Diseases of the Reptilia. Published Academic Press.
Frye, Frederic (1991) Reptile Care: An Atlas of Diseases and Treatments. Published T.F.H. Publications.
Marcus, L.C. (1981) Veterinary Biology and Medicine of Captive Amphibians and Reptiles. Published Lea & Febiger.

Author: Bruce Maclean B.Sc., B.V.M. & S., M,R.C.V.S.

Editors Note: Reproduced with kind permission from the Reptillian Magazine
This site has information on the following genera of Ratsnakes ... Spilotes, Spalerosophis, Ptyas, Zamenis, Elaphe, Rhinechis, Senticolis, Pseudelaphe, Pantherophis, Bogertophis, Orthriophis, Gonyosoma, Oreocryptophis, Oocatochus, Euprepiophis, Coelognathus, Archelaphe