
I think they are the same thing, just a magnifying glass really. Some people use a microscope. I couldn't get enough saliva from my dogs, they aren't a "droolly" sort of breed.
You get a picture instruction leaflet with it that shows the fearning patterns. I looked the patterns up on the internet for dogs. They all looked the same to me though, so I gave up on it, but some people swear by them.
Liz