If you still have to medicate your leos after two months, either something was missed in the fecal test(s) or you're letting your leo re-infect itself by not keeping things sanitary. Personally, I think taking them to the vet repeatedly is only going to cause your leos more stress, which will count against their immune system.
Since you're treating with Panacur, I'm guessing your leos have hookworms or pinworms. Hookworms tend to be more debilitating of the two and require at least 2-3 weekly doses. With any parasitic infestation, it's best to clean the tank everyday to ensure a quick recovery. At least replace the substrate everyday, wash out the humid hide, and be sure to clean the food and water bowls. Hookworms in particular are troublesome. Under optimal conditions, the eggs deposited in your leo's poop can hatch after just a few hours, then a certain stage of the larvae can penetrate the skin of the host and re-enter the body. There could be migrating larvae in your leos that are totally unaffected by the medication, which is why the follow-up doses are required. You should also double check that your feeders aren't the source of your leos' parasites.
Anyway, if you're so unsure about your vet's treatment, find out what parasite(s) you're dealing with and do some research on your own. Some require more work to get rid of than others, and you can't expect medicine alone to do the job.
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chickabowwow
