Dogs are very sensitive animals when it comes to sniffing out anything fishy or that which is not palatable. In fact, some dogs survive poisoning and then develop this ability to detect the same poison in food even in small quantities. Dogs can treat drugs as belonging to this category because not only do they have an unpleasant taste but they also have some side effects ranging from nausea to sweating. I suppose the best method is not to crush the pill and mix it with food as many people are won't to do. This is because this will increase its surface area and make it easier to detect. The best plan is to coat or embed the silk in steak and them give it to the dog. I don't suppose a bolus gun would work with a dog because they are prone to stress and fear and this would not be humane thing to do.
Our first dog was ferocious and it has the tendency to bite so what we do when there is a pill to be given is to crush the pill in a tablespoon and fill it with condensed milk. The sweet taste of the condensed milk somehow deadens the bitterness of the pill. At first, the dog would look suspicious so the trick we have developed was to give it just condensed milk first. And after taking the first tablespoon of sweet milk then it will surely take the second and that comes with the crushed pill already.
Our dogs now are the small type and we don't need the condensed milk. We just open their mouth wide and drop the pill inside then close shut their mouth for a few seconds. That's it.
When my dog's urine turned orange, I brought her to the vet. He prescribed tablets to her. I sometimes just shove it down there with my finger. Sometimes I ground the tablet to fine bits so it'll be easier to put in her food. The first option is better for me anyway.
Dogs have a very keen sense of smell, their olfactory faculties are well developed and the moist snout aperture is responsible for processing this. When it comes to chemical substances like pills, dogs may regard them as poisons. Some dogs are very good at this and they retain the memory of substances that elicited negative side effects on their physiology. Unlike human pills which are sugar coated to cheat the palate, dog pills are in their raw form and it goes without saying that they are bitter. Sugar coating them will not improve matters since canines don't have a sweet tooth. The best strategy in my opinion is to mix the dog food with the pill crushed into a powder to obfuscate the sense of smell. This should be done when serving the dog's favourite dish, for example raw steak. The other feasible alternative would be to use a bolus gun but again, this would require one to institute a method to restrain the animal which is likely to stress it. This might result in future resistance as dogs are sensitive to fear. A good turn deserves another.
All of the above mentioned methods will work, some easier than others, depending on the dog. I like mixing the medicine in with soft food or a small meatball ; but sometimes, if it is a small dog that chews everything and doesn't just gulp food down, they still do not get the medicine .
Another way that has worked for me is to dissolve the medicine when it is in pill form, and then mix it with a little milk or broth, and then put it in an eye dropper. It is much easier to use the eye dropper to squirt liquid down a dog's throat than it is to stick you finger in their mouth and push down a pill, while trying not to get bit by the frantic dog.
When I had puppies, they had to be wormed every few weeks, and the eye dropper method was the very simplest way to do it.
If the medicine is mixed with milk, or something that tastes good to them, then they will not fuss about swallowing it . This is really similar to @corzhens method, except I used an eye dropper instead of a spoon.