Usually when you have something like that, it is a good idea to put it in a ziploc bag or other sealed container in your fridge. Not freezer. Then get it to the vet ASAP for testing, before it can degrade.

Since you don't have it anymore, you can still bring the photo to the vet. It is better than nothing. I'd also consider bringing the photo from the other thread, so the vet can compare the 2, knowing the diagnosis on the other one was tapeworm. Just make sure your vet understands which one is from your animal!

EDIT: I agree with McKinsey's suggestion to get it out of the trash if possible.