If you have a lot of animals it is cheaper to learn how to do it yourself. There is a website that sells kits and identification charts. Just do a google search. The most expensive part is the microscope. They can be very expensive for a good one. I got a steal on the used one I bought for $100.

What you want is a fecal floatation. Not a smear. Floatation seperates the parasite eggs from other material (poop).

For floatations you need the following.
Good Microscope (at least 400x)
Fecalyzer Test Kits
Fecasol Solution
Slides and Slide Covers

Also this is a good book: "Understanding Reptile Parasites" by Roger J. Klingenberg