Short answer
The most common parasites in leopard geckos are pinworms and coccidia, which often cause no harm in healthy geckos. Heavy burdens, and the more serious Cryptosporidium, cause weight loss, diarrhea, smelly droppings, loss of appetite and poor growth. Only a fecal test by a vet can confirm parasites. Do not dose dewormers yourself: the wrong dose can kill a small gecko. Test every new gecko and book a yearly fecal check.
The common parasites
ReptiFiles names pinworms and coccidia as the most common parasites in leopard geckos, and says that in otherwise healthy geckos they often do not cause a problem. Stress can weaken the immune system until they do.1
| Parasite | What vets describe |
|---|---|
| Pinworms (oxyurids) | Heavy burdens cause loss of appetite, diarrhea, weight loss and slower growth2 |
| Cryptosporidium | Failure to grow, diarrhea and typically rapid weight loss2 |
| Coccidia | Common; a problem mainly when the gecko is stressed or unwell1 |
Signs to watch for
- Drastic weight loss, especially during brumation12
- Diarrhea, or unusually smelly droppings1
- Abnormal droppings or constipation together with weight loss, which the RSPCA calls potentially serious4
- A juvenile that stops growing2
- Loss of appetite2
See our weight guide for how to judge the tail.
Testing
The only way to confirm parasites is a fecal test.1 A vet examines a fresh sample under a microscope for coccidia, protozoa and worms.3
- New gecko: VCA recommends a vet check within two weeks of bringing a reptile home, and a fresh fecal sample for parasite testing.3
- Every year: the University of Liverpool vet practice recommends a yearly check with a fecal test.5
Treatment
If the test finds parasites, your vet will give a dose or two of dewormer, which ReptiFiles says should clear up the problem.1 ReptiFiles warns against buying and dosing dewormers yourself unless you are very experienced, because an incorrect dose can kill a gecko.1
Prevention
- Quarantine new reptiles and test them before they share space or equipment.
- Spot-clean droppings promptly.
- Keep stress low. ReptiFiles says stress can weaken the immune system until parasites become a problem.1
- Buy feeder insects from a reliable supplier, and never feed wild-caught insects.
Common questions
Can I buy a dewormer and treat my gecko myself?
ReptiFiles advises against it unless you are very experienced in dosing reptile medicines, because an incorrect dose can kill a gecko. Have a vet test a fresh sample and prescribe the right drug and dose.
Is Cryptosporidium curable in leopard geckos?
Usually not. Vet Times says the experimental treatment is hard to get and does not always clear the infection, and advises that geckos showing signs be euthanized because the disease keeps progressing and spreads easily. Signs are failure to grow, diarrhea and typically rapid weight loss. Any gecko losing weight fast should see a vet promptly for testing.
How often should my gecko have a fecal test?
Test every new gecko, ideally at a vet check within two weeks of bringing it home, and then at least once a year with its annual checkup.
Sources
Numbers in the text link to these sources. We checked each one on the date shown.
- 1Leopard Gecko ParasitesReptiFiles. Checked Oct 29, 2026.
- 2Management, care and common conditions of leopard geckosMarie Kubiak. Vet Times. Checked Oct 29, 2026.
- 3Veterinary Care: New Reptile VisitGregory Rich, DVM; Rick Axelson, DVM. VCA Animal Hospitals. Checked Oct 29, 2026.
- 4How to care for a leopard geckoRSPCA. Checked Oct 29, 2026.
- 5Leopard gecko husbandry and careFilipe Martinho, MRCVS. University of Liverpool Veterinary Practice. Checked Oct 29, 2026.
Update history
- : First published.
- : Re-checked every claim against its sources; corrected wording, numbers and attributions.
HerpWise Editorial · About the author and review process
HerpWise Editorial summarizes published veterinary, welfare and specialist care guidance. The sources and check date are listed on each guide. Veterinary review is credited separately when completed.
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