If your dog is persuasible, you can let him sit and stay before feeding him tablets or solid-like drugs.

Let your dog open his mouth, and put tablets in the depths of his mouth as soon as possible, then close its lower jaw gently and lift his head up, stroke his neck to help the dog engluts the tablets.

As well, you can mix tablets into the food your dog love to eat, aslo you can grind tablets into powder, then feed your dog. If you feed your dog medicinal liquid, you should get a injector from veterinary clinic or buy one from drugstore, it's used for feeding your dog medicinal liquid.

You should inject the medicinal liquid into dog's mouth, rather than his throat, which may drop medicinal liquid into his windpipe, then  support his lower jaw by your hand until he engluts the tablets.