can you tell the difference between sheepy tapeworm and the doggy dangerous tapeworm?
Yes. If you can see tapeworm segments in the sheep's poo it is the sheepy tapeworm.
Unfortunately the dangerous doggy one is not detectable in the sheep except through symptoms and post mortem. There is no treatment for the sheep, control has to be by worming the dogs. If you have sheep on public footpaths, there is nothing you can do except educate the public and pick up any dog poo you see.
The tapeworm has a two-stage lifecycle. In the terminal host it lives in the gut and makes eggs which it sheds as segments in the poo. The eggs are then ingested by the intermediate host, migrate through the tissues and make cysts wherever they land up in the tissues. The terminal host is infected when it eats the cysts in the carcase.
So the sheepy tapeworm is the one that lives in the sheep's guts and you see segments in the poo. It doesn't really do any damage to the sheep, although I guess it must use up some of the nutrition in the food the sheep eats. The eggs are eaten by pasture mites, and their infected bodies are then eaten by sheep on the grass, to start the cycle again.
The doggy tapeworm lives in the dog's guts and you see segments in the dog's poo. The segments crawl up the blades of grass and are eaten along with the grass by the sheep. They then infest the sheep's tissues, making cysts. Often there are no symptoms, but the cysts will be found at the abattoir and any such tissue condemned. In a really bad infestation the animal will die from the damage to the tissues.
There are also tapeworms in other carnivores (foxes, cats) as the terminal host, ie, shedding eggs and in other herbivores (rabbits mainly) as the intermediate host, reinfecting the carnivores as the latter eat the carcase.