7.5 month old won’t take fluids

[AS94x]

I’m wondering if anyone can help. My little boy is 8 months on the 4th June 2019 and for the past week has been off his fluids but still taking his solids. He seems to taking less and less as the days have went on and isn’t interested in having milk, juice or water. We tried everything from changing teats, feeding in a dark/quiet room, adding formula in a sippy cup, water into bottles etc. and nothing is working.
He used to take 3 7oz bottles and 1 4/5oz bottle plus 3 meals a day, but now we’re lucky if he is taking 15oz in 24 hours. My HV told he should be having at least 18 - 20oz in 24 hours but there’s no way he’s having that. He won’t even eat his cereal with formula milk in it.
Yesterday he wasn’t peeing much so he was at out of hours GP but they said because he seems hydrated he’s fine. Again he hasn’t been peeing that much.
I noticed today he has a red sporty rash on his forehead and he has a big white lump on the front of his gums, could this related teething? Do babies go off liquids totally when teething or is there something I should do?

[ComeAlive]

My babies were like this. I think they got fed up with formula milk so their intake dramatically reduced. I know it can be worrying but I would persevere with giving bottles (mine had one in the morning of c150ml then one before bedtime c150ml) then I would make up fluid intake by giving milky porridge (either formula or full fat milk) water during the day, lots of yoghurt, water and milk added to their solids. If you haven’t already get lots of different cups as the novelty of that can help. I’m not sure if this is teething related or perhaps due to the lump you have found which I would get checked out, likewise the rash. I also found going’s up a teat size helped as they seemed to get bored easily with trying to suck milk as they got older. Bear in mind also that formula will be calorie dense so it’s to be expected that if they are eating well during the day that they won’t want that much formula on top of that.