Ladybirder, I have 7 cats over the age of 16 and have often had to find weird and wonderful ways of getting medications down them and have found 'powders' one of the hardest. Then I had the idea of buying a packet of the thinnest cigarette rolling papers you can get (either blue or silver Rizla's) I'd cut the sticky bit off then cut the paper in half, so you have a little square, put the powder in and twist the paper into a small ball, pop it into some favourite food and more times than not, it gets eaten along with the grub (cos they don't pick up on the scent of the powder). Might be worth a try at least.