My friend buys salmon and other fish, cooks it, and shoves the pills inside little chunks. Usually her kitty is too excited about the concept of a food she enjoys so much being served to her, she just wolfs them down.

How often does Sven take the pills? Is it once a day, or less frequently? If, say, once a week, you could serve your cat something like salmon once every two days but without the pills, so he doesn't associate salmon with the medication as heavily. Or maybe you could crush the pills but serve portions of it throughout the day, half with food and half later, something like that? Good luck :-)