Parasites are easily, easily transferable from one animal to another. It doesn't have to just be leopard gecko to leopard gecko. Could be leoprd gecko to bearded dragon. Or anole to leopard gecko. That's why people do not advocate housing different species together.
Parasites are transfered by contact with infected fecal matter. I do not even handle my quarantined geckos unless I wash my hands with antibacterial soap before each one, and in between.
Parasites are cured by going to the vet. Bring a fresh fecal sample to the vet for a smear, stain, or float (different types of fecal tests).
Separate the cagemates if you haven't done so already. Make sure to keep their enclosures spotless. Clean it every day. Make an appointment with a qualified herpetological veterinarian. Do not rely on forums to help you diagnose problems because of two reasons. Most of us (me included) are not vets, just gecko enthusiasts. Also, we cannot see the gecko or test it to get to the root of the problem.
Take it to the vet.
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Josh Ellis
My Email
Geckophiles.com
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