It is not mandatory, but definitely a good idea. keep in mind chams are in the top ten list of reptiles with parasites, so he will possibly test positive for something. so, don't be alarmed. i think it is a great idea and very responsible of you to put forth the effort and cash of doing so. especially in todays financial times (not being political here, just an everyday observation). If you can afford it, please go. it will put your mind at rest also. currently over any issues or in the near future. you will know already that everything checked out and you are probably over reacting over the food stain on him (example).