Captive dart frogs are hardy once established, but their small size and permeable skin make them vulnerable to pathogens. Early recognition of common diseases can save frogs, protect collections, and prevent the spread of notifiable diseases in the UK. This in-depth guide covers bacterial, fungal, viral infections, parasites, treatment options, and biosecurity protocols.
Understanding Dart Frog Immunity
Amphibians rely on antimicrobial skin peptides and a balanced microbiome to fight disease. Stress, poor husbandry, or sudden changes in temperature and humidity can suppress immunity. Ideal ranges for dart frogs are:
- Temperature: 22–26 °C
- Humidity: 70–100 % RH
Provide visual barriers, live plants, and microfauna to reduce stress and simulate natural conditions.
Bacterial Infections
Red-Leg Syndrome
- Cause: Aeromonas hydrophila complex
- Symptoms: Redness on legs/belly, lethargy, loss of appetite
- Treatment: Enrofloxacin bath (5 mg/L for 7 days), supportive care
Flavobacteriosis
- Cause: Flavobacterium columnare
- Symptoms: Skin ulcers, necrotic gills in tadpoles
- Treatment: Oxytetracycline bath (50 mg/L), full disinfection of enclosure
Fungal Infections
Chytridiomycosis (Bd)
- Cause: Batrachochytrium dendrobatidis
- Symptoms: Excess shedding, lethargy, uncoordinated movements
- Diagnosis: Skin swab + qPCR (Pathovet UK)
- Treatment: Itraconazole bath (0.01% for 5 mins daily, 7–10 days); raise temps to 26°C; deep clean vivarium
Saprolegniasis
- Common in eggs and tadpoles
- Treatment: Methylene blue bath (2 ppm), improve water flow and cleanliness
Viral Infections
Ranavirus
- Transmission: Via water, contaminated hands, or ingestion
- Symptoms: Sudden death, red blotches, internal organ failure
- Diagnosis: PCR test (Pathovet or APHA); histopathology
- Treatment: No cure; isolate or euthanise; report to APHA; disinfect with 3% bleach (10 min contact)
Endoparasites
| Parasite Type | Example | Symptoms | Treatment |
|---|---|---|---|
| Nematodes | Rhabdias spp. | Wasting, breathing issues | Fenbendazole 50 mg/kg orally x 3 days |
| Protozoa | Entamoeba ranarum | Diarrhoea, prolapse | Metronidazole 20 mg/kg bath |
| Tapeworms | Spirometra spp. | Visible lumps (larvae) | Praziquantel 5 mg/kg IM |
Test new frogs with fresh faecal exams at least twice annually or after unexplained illness.
Ectoparasites
- Mites (Hirstiellidae): Small red or black dots, often visible at night. Treat with Hypoaspis miles or apply mineral oil.
- Fly Larvae/Leeches: Rare, but require immediate manual removal and hygiene review.
Diagnostic Tools in the UK
| Test | Sample | Provider | Approx. Cost |
| Chytrid & Ranavirus (qPCR) | Skin swab | Pathovet UK | £28 |
| Parasite Screen | Fresh faeces | Pinmoore Animal Lab | £15 |
| Bacterial Culture | Swab | Surrey Diagnostics | £38 |
Ship samples in sterile containers; use cold packs in warm weather.
Treatment Best Practices
- Isolate affected frogs in clean, paper-towel-lined tubs
- Use species-appropriate heat and humidity
- Vet-prescribed topical or oral treatments only
- Avoid human medications or home remedies
- Support with calcium, UVB, and hydration (Pedialyte 1:3 dilution)
Quarantine & Biosecurity (UK Model)
| Phase | Duration | Actions |
| Initial Isolation | 60 days | Gloves, no tool sharing, daily checks |
| Baseline Testing | Day 21 | Swab + faecal tests |
| Repeat Testing | Day 42 | Ensure clearance of parasites/pathogens |
| Integration | Day 60+ | Only if both tests are clear |
Always clean tools with 1% Virkon S or F10SC. Work from healthiest to newest animals.
Building a Disease-Resistant Vivarium
- Use springtails and isopods to break down waste
- Keep ammonia <0.05 ppm; nitrate <10 ppm
- Disinfect new plants in 5% bleach for 90 seconds
- Provide UVB (2%) and varied nutrition
- Ensure airflow to reduce fungal hotspots
Record Keeping & Ethics
- Log feeding, shedding, weights, and treatments
- Keep lab results for 5 years (especially for breeders)
- Notify customers of any known health history
- Share anonymised data with conservation databases when possible
FAQs
Q: How often should I test my frogs for chytrid?
A: Every 6–12 months for display frogs; every 3 months for breeders.
Q: What’s the safest disinfectant for vivarium use?
A: 1% Virkon S or F10SC; always rinse and dry thoroughly.
Q: Can I use human antifungals?
A: No. Only vet-approved itraconazole baths are safe and effective.
Q: Is UVB lighting required?
A: Optional but recommended; low-level UVB improves calcium absorption and immunity.
Featured Image
- Filename: dart-frog-health-check-exotic-vet.jpg
- Alt text: Exotic vet inspecting a green and black dart frog for skin lesions under a magnifying lamp
- Description: Routine health checks help UK keepers detect early signs of bacterial, fungal or parasitic disease.
