Giving tablets is always a wrestling match in our house, but I did find a solution. I hide them in a little bit of peanut butter. He thinks he's getting a treat.
My Golden Retreiver had the same problems. I tried different foods, washes etc. It ended up being an underactive thyroid. He's now on medication, his coat is growing back and he looks a million bucks. He also has a lot more energy too.
Renee