Well, that was quick, guru vet says give him wheatgrass!
She has no idea why fur would be falling out, but might be due to meds, even though it is rare. His immune system may be more stressed than most pets would be.
There is one other unlikely thing too, sometimes people and cats suffer hair loss from flax oil, but apparently this rights itself and you grow shiny new fur/hair. It is rare though. If this was the case it would mean that the dose you are giving might be too high for him, but hard to tell. She advises to keep an eye on it, and if fur doe snot begin to grow stubble undercoat again as weather gets colder, then cut down a bit and see if that makes any difference.
Anyway, she recommends wheatgrass to improve fur and vitality. She gives it to old cats to help stiffness, and dogs. If you look on google there are videos of cats eating it, and you can buy kits. I think I've seen them at pet shops. I don't know if Dougal would eat this. I might try mine on some too ....
It makes the system less acid, balances the ph. I used to take it, made smoothies. You can get the powder which you could mix in his food, but it is more fun for them to 'hunt' the actual grass and you would not want to put him off his Felix. I think I should take it again too. Funny how we have these 'health' spurts and then forget all about it. I'm sure I have some ancient vitamins in the cupboard.
She said just check with your vet first to make sure they agree it would not interfere with treatment, but shouldn't.
http://www.amazon.com/Dog-Cat-Wheatgrass-Growing-Kit/dp/B000E7ZJWS
cats eating it - but being fed! I thought the whole idea was they fed from the tray ....
http://www.youtube.com/watch?v=LOmn2l1O73c
Oh - I like this one better - look at the last video, Buster is great! :<3:
http://catgrass.org/cat-grass-videos/cats-eating-wheat-grass-videos