If dough made for dogs is also eaten by shepherds (meaning that it’s fit for human consumption), it is obligated in challah, it may be used to make an eiruv and a shittuf (the latter of which enables the residents of several courtyards to carry in their common alley on Shabbos), one bentches and forms a zimmun (the call to bentch) over it, it may be made on yom tov, and one can use it to fulfill his obligation to eat matzah on Pesach. If shepherds don’t eat it (meaning that it’s not fit for human consumption), it is not obligated in challah, it may not be used to make an eiruv or a shittuf, one does not bentch or form a zimmun over it, it may not be made on yom tov, and one cannot use it to fulfill his obligation to eat matzah on Pesach. In either case, it can contract ritual uncleanliness.
If one eats challah or terumah intentionally, he is liable to a Divine death; if he eats them unintentionally, he must repay the value plus a fifth. These things may only be eaten by kohanim, are the kohein’s property (as opposed to Temple property), are cancelled out in the percentage of one portion to 100 portions of regular produce (chullin), one must wash his hands before handling them, a ritually-impure kohein who immersed in a mikvah must wait until nightfall to eat them, one may not separate from clean produce for unclean produce, and one may only separate them from produce that is nearby and whose work has been completed. If one declares all the grain on his threshing floor to be terumah and all of his dough to be challah, he has accomplished nothing; one must retain possession of at least some of his produce and dough.