The signs are typically reduced appetite, lethargy, and the big one is very stinky poo. Sometimes they are okay except for the poo smelling. Depends where you get a fecal done - at a vet, probably $30-50 at a vet. You can also get one done by Cheryl and beardeddragon.co. They are much cheaper - I want to say $5-7, but don't quote me on that! You would just have to send it to her in the mail following her directions.
You can get a cheap fecal done from Cheryl on beardeddragon.co and then order your panacur from her too, I think! I know breeders who give panacur to their dragons every spring as a preemptive measure against parasites. I am noticing some stinky poo lately, I will likely be ordering a float myself
It is not recommended to treat your dragon for parasites without a positive fecal exam. Many of the medicines used are very harsh on their systems and should be used only when necessary.