huge sympathies here.....I have been thro tis with mine.....three times in fact!!!
I have 5 kiddies, 3 allergic to milk and the other 2 also suffer from milk 'build up' which can give them ecxma (?), altho they do still have normal cows milk.
I too am allergic to milk and am currently finding it hard myself to gain weight, altho the kiddies now gain well, even tho I had all three drop off the centiles when small!
anyhoo.......
unless medical advice has changed drastically since mine were babies (and I do appreciate that it does, even in 5yrs!), then at 11mths there should be now real reason why not to start using soya in cooking.
when my last was small (he is now 5), the advice was 6mths and altho I did use prejomine (the non-allergy milk that he was on), right up until his fifth birthday for a main drink (he now has soya), soya was in the food from 6mths without major effect.
for weight gaining....
mashed avodaco, banana and apple was a great one for mine. add to dairy free yogs, spread on toast (will need protection for this for carpet and clothes as it does stain), or even put on top of weetabix with his normal milk (expressed BM I assume).
go up to 6small meals a day, with snacks to if possible. If he is losing seight then his tummy will be tiny.....so small and often is the key to help his appetite to improve.
raisins/bananas/dairy free biscuits/toast with honey (well......not recommended just yet but he is nearly there/toast with marmite.
tesco value scotch pancakes are milk free (they are my mainstay if I am off colour) with spreads of choice on top.....jam/dairy free choc spread (the best one is in sainsburys) or the banana/avocado stuff on top.
ermmmmmm......
will think more and come back.
ooh, if you aren't yet doing so tho, vitimin drops are a must!!!!