When you get your gun, your vet should show you how to use it. The most difficult aspect of using the gun is getting your cat to open his mouth. The gun will more or less shoot the pill in the cat’s mouth, and down his throat. You’ll need to hold him tight, to make sure that he doesn’t wiggle his way loose. Once you have his mouth open, you’ll need to squeeze the trigger and pull the gun away quickly. After the pill has been inserted, make sure you give your cat a treat.
If you aren’t comfortable using the gun, you can always try giving your cat his pills by hand. To do it this way, you’ll need to hold your cat still, and open his mouth with your hand. Once you have his mouth open, you should aim for the back of his throat and throw the pill in. Once it is in his mouth, you should close his mouth with your hand and hold it shut for a few moments. This way, your cat will swallow the pill if he hasn’t already.
If you can’t get any of the above techniques to work, you can always go to a local pharmacy and get them to a make flavored gel or liquid using your cats medication. You should use this as a last resort though, as it can tend to get expensive.