🧼 Bacterial Dermatitis in Reptiles: A Vet’s 2025 Guide to Skin Infections, Shell Rot & Husbandry Solutions | Dr Duncan Houston BVSc

Bacterial dermatitis — also known as shell rot, belly rot, blister disease, or SCUD — is a common yet serious skin condition in pet reptiles. It may start as a simple wound or blister but can progress to systemic infection, loss of appetite, and death if untreated. 🐢⚠️

This 2025 vet-authored guide will walk you through everything you need to know about identifying, diagnosing, and managing bacterial dermatitis in your reptile. 🧪🦎

🔬 What Is Bacterial Dermatitis?

This condition is caused by bacterial invasion of the skin or shell, often due to trauma or poor husbandry. Instead of healing normally, affected areas form pustules or blisters that rupture, leaving open wounds that can deepen over time. 🩸

Unlike viral or fungal conditions, bacterial dermatitis usually presents as localized or widespread skin ulceration, swelling, and discoloration. 📛

🔍 Common Names & Forms

• 🐍 Blister Disease – seen in snakes, often on the belly; linked to poor humidity and dirty substrate
• 🐢 SCUD (Septicemic Cutaneous Ulcerative Disease) – shell ulcers in aquatic turtles due to poor water quality
• 🦎 Devrieseasis – caused by Devriesea agamarum; affects desert-dwelling lizards, forming bumpy lip lesions

📉 What Causes It?

The root cause of nearly every case is poor husbandry that weakens the immune system or damages the skin. Common predisposing factors include:

• 🌡️ Incorrect temperature or humidity
• 🚱 Dirty water or substrate
• 🧱 Sharp cage furniture or small enclosures
• 🍽️ Nutritional deficits, esp. Vitamin A deficiency
• 🦷 Rubbing or trauma from escape behavior
• 🦠 Previous wounds or burns

Mixed infections with Gram-negative bacteria (e.g., Pseudomonas) are common. 🧬

📌 Species Most Affected

While all reptiles are susceptible, high-risk cases include:

• 🐢 Aquatic turtles – prone to shell rot (SCUD) due to stagnant water
• 🐍 Snakes – blister disease from poor substrate or high humidity
• 🦎 Bearded dragons, iguanas – tail-tip or face injuries from cagemates
• 🦎 Green water dragons, basilisks – nose trauma from escaping attempts
• 🧬 Color morphs – potentially linked to weaker immune function

🧠 Signs of Bacterial Dermatitis

Signs depend on location and severity. Look for:

• 🟡 Blisters, ulcers, or discolored patches
• 🧱 Thickened, bumpy, crusty skin
• 💤 Lethargy, anorexia, depression
• 🐾 Swelling around limbs, mouth, or tail
• 👄 Lip nodules (esp. in dry-climate lizards)
• 👁️ Eye swelling or cloudiness (subspectacular abscess)

In severe cases, systemic infection (septicemia) can occur — a life-threatening emergency. 🩺

🔬 Diagnosis: What to Expect

Your vet will gather a thorough history and perform a physical exam. They may suggest:

• 🧫 Cytology: microscope exam of blister fluid or tissue
• 🧪 Culture & sensitivity: identifies bacteria and best antibiotic
• 🔍 Biopsy (histopathology): definitive test for diagnosis
• 📸 X-rays or ultrasound: to assess internal damage
• 🩸 Blood tests: to check for systemic infection

Many skin lesions can resemble burns, fungus, or vitamin deficiencies — diagnosis is key. 🎯

💉 Treatment Plan

Step 1: Supportive Care

• 🌡️ Raise core temperature to optimal zone
• 💧 Rehydrate with fluids (injections or soaking)

Step 2: Surgical or Topical Management

• 🛠️ Surgical debridement to remove infected tissue
• 🧴 Topical antibiotics (e.g., Silvadene cream)
• 📋 Systemic antibiotics (oral or injection)

Step 3: Environmental Correction

• 🚿 Improve hygiene and water changes (for turtles)
• 🌡️ Adjust humidity and lighting
• 🧼 Eliminate sharp or abrasive decor

🐢 Turtle-Specific Note:

Dry-docking (keeping aquatic turtles out of water for 1–2 hours/day) can speed healing when used with topical treatment. 🐢🧴

⚠️ Don’t Stop Treatment Early

Complete the full course of antibiotics and revisit your vet for progress checks. Some lesions may take weeks to resolve fully. 🚫📆

📈 Prognosis

With prompt diagnosis and complete treatment, most reptiles fully recover. However:

• 🧬 Scarring is common — may appear pale, wrinkled, or hairless
• ❌ Recurrence likely if husbandry isn’t corrected

In cases with systemic infection or deep wounds, prognosis is guarded. 🔬

🛡️ Prevention: Your First Line of Defense

• 🌞 Provide proper UV lighting and basking zones
• 💧 Maintain clean water and appropriate humidity
• 🧼 Sanitize substrate and décor regularly
• 🍽️ Feed a balanced diet rich in vitamin A
• 👨‍👩‍👦 Limit stress from overcrowding or bullying
• 🚫 Quarantine new animals before introduction

📱 Need Expert Help? AskAVet.com

If your reptile has skin blisters, sores, or ulcers — don’t guess. Download the Ask A Vet app for instant access to exotic pet vets who can help you diagnose, treat, and prevent bacterial dermatitis 🐾💬.

With prompt care and the right environment, your reptile can bounce back beautifully. Let’s keep those scales and shells strong, clean, and healthy in 2025 and beyond. 💚🦎