Jackie,
You can perform parasite examinations from fecal samples yourself with the right equipment, and a little know how, but my guess is you probably need the vet as Marcia said because this needs to be checked right away. Those threads could have been tapeworm strands/segments or other worms like ascarids (roundworms).
Take a FRESH fecal sample to a veterinarian, then ask that a fecal float and fecal smear be performed. These two tests can determine lots concerning parasites. The Leo probably does not have to see the vet at all for testing, but may have to go to have medications administered. Then again it is possible if they are parasites the vet will sell you the meds and have you administer them if you want. Some meds can easily be given with food. Treatment will quite possibly consist of orally administered medications.
Only use a well experienced herp vet. and make sure the vet has seen lots of reptiles before.
The parasites may or may not be easily transmitted to other animals in your collection. This depends in large part as to whether or not they have a direct life cycle, or indirect life cycle.
Regarding parasites, a direct life cycle means they are fully capable of completely reproducing inside a single host animal and do not require an intermediate host animal for any part of the life cycle - therefore potentially constantly reinfesting. Any eggs, larvae or adults that are excreted can be consumed by the same critter, or by another creature of the same type (such as a cage mate) and it will then be infested too. This can lead to rapid buildup of the parasite load. Hookworms are a direct lifecycle parasite; they can decimate an animal rapidly under captive conditions.
Indirect life cycle parasites require an intermediate host or hosts -of another animal type for the various stages of the life cycle to develop. For instance the eggs may be passed in the feces of a lizard, but may have to be ingested by an insect, or snail, or fish or whatever, to hatch and develop the larvae. Then when the intermediate host is consumed by a larger predator, the predator can become infested. These are not easily/readily passed onto cage mates as far as I understand unless possibly an adult is passed in the feces or regurgitated and then eaten by a cage mate. Roundworms are one such example.
The best thing to do is get a fecal sample to a vet. Use a fresh sample, as fresh as possible. Don't use a dried out one. Don't freeze it. Try to get it right to the ver right after it is passed. Sometimes a vet will give you a collection tube in advance. Call the vet first and ask.
Make certain to quarantine this animal and any others that had been kept with it recently. Keep the animals' enclosures extremely clean of any feces. Use paper toweling as a substrate (easier to clean). If it is a direct life cycle parasite, then any eggs passed in the feces can be ingested by the lizard and will develop inside the lizard leading to an extremely rapid parasite load buildup. Keeping it clean helps delay any buildup. Wash before and after handling any of these animals. Besides not wanting to transmit parasites to other lizards, you do not want to run the outside risk of picking up any yourself. I doubt that most reptile parasites are capable of infesting people, but I would not want to chance it myself and; I believe that some roundworms and tapeworms that infest herps can cause problems in humans.
Good luck.
Best regards,
Glenn B
