Vet Guide 2025: Chytridiomycosis in Amphibians 🐸 by Dr Duncan Houston 🩺

Hello! I’m Dr Duncan Houston, BVSc and founder of Ask A Vet. Chytridiomycosis—commonly called “chytrid”—is a devastating fungal skin disease in amphibians caused by Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). With global population collapse in hundreds of species, understanding this disease is vital. This 2025 guide addresses its biology, clinical signs, diagnostics, treatment strategies, and essential prevention measures to protect both pets and wild amphibians.

1. What Causes Chytridiomycosis?

Chytrid fungi infect keratinised skin of adult amphibians (and mouthparts of tadpoles), disrupting osmoregulation and respiration through electrolyte imbalance and heart failure—frequently lethal :contentReference[oaicite:3]{index=3}. The disease emerged in the 1990s but likely predates this :contentReference[oaicite:4]{index=4}.

2. Global Impact & Species Affected

Bd/Bsal has been detected worldwide—including Americas, Australia, Europe, Africa—with over 500 amphibian species affected; ~90 extinctions are attributed to it :contentReference[oaicite:5]{index=5}.

3. Recognizing the Signs

• Gray‑white sloughing skin, reddening, ulcerations, thickening (hyperkeratosis) :contentReference[oaicite:6]{index=6}
• Lethargy, anorexia, loss of righting reflex, abnormal posture :contentReference[oaicite:7]{index=7}
• Larvae may show discolored keratinized mouthparts :contentReference[oaicite:8]{index=8}
• Electrolyte loss leading to cardiac arrest :contentReference[oaicite:9]{index=9}

4. Diagnosis & Testing

• Skin swab PCR to detect Bd/Bsal DNA :contentReference[oaicite:10]{index=10}
• Wet‐mount of slough, histology showing fungal thalli/sporangia :contentReference[oaicite:11]{index=11}
• Clinical signs plus environmental history: water temperature, exposure risk

5. Treatment Approaches

5.1 Antifungal Baths

Medicinal baths (e.g., itraconazole) remain standard: bath solutions given daily for 5–10 days are effective but carry toxicity risk, especially in larvae :contentReference[oaicite:12]{index=12}.

5.2 Heat Therapy (“Frog Saunas”)

Bathing amphibians at 28–32 °C for several hours daily can clear Bd, demonstrated successfully in captive populations without chemicals :contentReference[oaicite:13]{index=13}.

5.3 Supportive Care

• Improve husbandry: clean water, stable humidity, minimal handling)
• Correct electrolytes; supportive fluids may help cardiac function
• Monitor weight, sloughing frequency, righting ability

6. Prognosis & Limitations

Early intervention can clear infection, but outcomes depend on species resilience. Larvae are risky; heat therapy is species‐specific :contentReference[oaicite:14]{index=14}.

7. Prevention & Biosecurity

• Quarantine all new amphibians > 4–6 weeks with PCR testing :contentReference[oaicite:15]{index=15}
• Disinfect tanks, nets, décor; avoid shared water systems
• Ensure tank temperatures fluctuate above 25 °C when possible :contentReference[oaicite:16]{index=16}
• Never release pet amphibians outdoors to avoid wild spread :contentReference[oaicite:17]{index=17}

8. Conservation & Global Significance

Chytridiomycosis is the most devastating wildlife disease recorded—threatening 30% of amphibian species :contentReference[oaicite:18]{index=18}. Controlled “frog sauna” reserves and probiotic skin bacteria (e.g. Janthinobacterium lividum) show promise as conservation tools :contentReference[oaicite:19]{index=19}.

9. Ask A Vet Support 🩺

If your amphibian shows skin sloughing, lethargy, or loss of reflexes—or you want help designing heat or antifungal protocols—connect to specialists via the Ask A Vet app. Send swab results, photos, videos, or tank data and receive tailored care plans. Visit AskAVet.com 📱

10. Final Thoughts

Chytridiomycosis is a global crisis that demands early detection, careful treatment, and strict prevention measures. In 2025, using antifungal baths or heat therapy—and reinforcing biosecurity—you can save your pet and support broader conservation efforts. With Ask A Vet’s expert backing, you’re never alone in the fight against this devastating disease. 🐸🌿

— Dr Duncan Houston, BVSc