Big surprise - they hate it. And they know why you're putting their halters on and unwrapping that crinkly paper cover. I go through a good amount of apples and carrots in bribery and rewards.
Except with Fritz - he LOVES worming day. That's because he's the only horse smart enough to take it in a more pleasant way. I cook up an oatmeal mash (one cup whole Quaker oats, 2 cups water, and about one-quarter cup brown sugar), cool, squeeze the whole tube of wormer into it, mix with grain until thick, then scoop big globs of it into the feeder. All my horses have been suspicious of that soft, gooey feel of the mixture and refused to eat it. But not Fritz. He knickers as soon as he sees me coming with the pan of oatmeal, and doesn't stop until he can dive into the sticky mess and lick up every last bit. I don't feed my horses sugar cubes or peppermint candy, so it's the only time he gets to OD on sugar. He can't wait.
If anyone has any other good ideas for making worming more pleasant, I'd like to hear them.