I've looked several times for bearded dragon health insurance, as I have 3 now, and I have never found one that covered reptiles that was even close to being worth it, especially for things like parasites. A fecal test and then antiparasitic meds or antibiotics/Antiprotozoan meds for coccidia aren't expensive enough to make the insurance worthwhile.
Maybe someone else can recommend one, but I doubt it. The bottom line to pet health insurance for reptiles is that it is basically only worth paying for if your beardie needs something very expensive, like surgery, or is diagnosed with cancer and needs chemo or radiation...As far as smaller, common health issues like parasites, bacterial infections, fungal infections, etc. most insurances don't cover any of these, and if they do it's much cheaper to just pay the vet out of pocket than pay the insurance premiums, deductibles, and copays.