Leopard Gecko Mouth Rot (Stomatitis): Signs & Treatment
| Cause | Usually bacterial, secondary to injury |
| Home treatment sufficient? | No — vet antibiotics needed |
| Early sign | Redness/swelling at gumline |
What it is
Stomatitis, commonly called mouth rot, is a bacterial (occasionally fungal) infection of the mouth lining and gums. It's typically secondary to an injury — a rough substrate scrape, a fall, or a bite from live prey — that lets opportunistic bacteria take hold.
Early signs
Look for redness or swelling along the gumline, small flecks of caseous (cheese-like) discharge, reluctance to eat, or excess saliva pooling at the corners of the mouth. Mild cases can look like nothing more than slight puffiness at first.
Why home treatment isn't enough
Diluted chlorhexidine rinses are sometimes used by vets as an adjunct, but stomatitis in reptiles is a bacterial infection that generally requires prescription antibiotics and, in advanced cases, debridement of dead tissue — a vet visit is the correct first step, not a wait-and-see approach.
Prevention
Avoid sharp-edged decor and coarse loose substrate, disinfect enclosures regularly, and separate any leftover live insects the gecko hasn't eaten within 15–20 minutes, since uneaten crickets in particular can nip a sleeping gecko's mouth.
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A single adult leopard gecko needs a 20-gallon long tank as an absolute minimum, with a 36x18 in (40-gallon breeder) footprint now considered the recommended standard — plus a secure lid, an under-tank heater on a thermostat, a thermal gradient, at least three hides, and a shallow water dish.
Set up in this order: substrate, then heat source wired through a thermostat, then hides and water dish, then decor — and run the whole enclosure for at least 24–48 hours to confirm stable temperatures before your gecko moves in.
Hatchlings can start in a 10-gallon tank or tub, juveniles do well in 20 gallons, and adults need a 20-gallon long as an absolute minimum — with 36x18 in (40-gallon breeder) now the widely recommended standard, not just an upgrade.
Heat a leopard gecko enclosure with an under-tank heater and/or overhead heat source (halogen or deep heat projector) wired through a thermostat — a thermostat is mandatory, not optional, and heat rocks should never be used.
Leopard geckos can survive without UVB using dietary D3 supplementation, but current husbandry guidance now recommends low-level UVB (roughly 2–6% T5) as best practice — it improves D3 synthesis, bone density, and natural behavior, and views on it have shifted significantly from older nocturnal-species advice.
Keep ambient humidity around 30–40% across most of the enclosure, with a dedicated humid hide raised to roughly 70–80% to support smooth, complete sheds.