11 week old stopped wanting milk. What to do next?

[ER1992]

I have an 11 week old boy who is formula fed cow and gate.
He was taking 6oz four times a day and 4oz at bedtime (28oz in total per day). Over the last week he will only take the full 6oz in the morning and then the rest of the day I'm lucky if he will take 3oz before stopping, pushing the bottle out of his mouth and not letting me get it back in for him to take more he just keeps spitting it out. He is sleeping through the night so isn't waking up hungry but he's definitely having a lot less the he had been.
He was weighed this week and HV said he should have put on a bit more by now (he is 11lb 4oz, birth weight was 7lb 4oz) and if he hasnt put on enough next time he will need to be referred to GP. Now he's eating less I'm concerned about his weight gain. He seems happy in himself but has started to chomp on his fist a lot and drooling could he have started to teeth which is putting him off his milk? Should I try change formula? Any other suggestions would be appreciated. I have changed his teat to the medium flow but this hasn't made a difference

Have you changed to the next teat size yet?

Sorry completely missed that.

My DS always fed less when he had a sore throat. You could pop to the GP who may spot it and they always told me feeding would pick up as soon as it was gone. It always did. From memory I don't think my DS drank as much as 6 ounces in one go at 11 weeks. I think it was 4 ounces per feed. You could try less each time but more often for a bit too.

Have you tried giving less milk in the morning then the rest a bit later? Say 3oz at 6am then 3oz at 7? When DS went off food GP suggested that I give him little and often and not to worry too much as long as plenty of wet/dirty nappies. I had to feed him 2oz of milk every 1 1/2hrs - just enough so he wasn't starving but enough to make him hungry iyswim?

Ah the sore throat could make sense as I currently have a sore throat so he could have caught that from me. He isn't happy if he has less than the 6oz first thing in the morning so while he's happy to have that then I'll keep giving it to him. I have read that after a growth spurt they tend to eat less because they don't need it so maybe this a long with a sore throat could be why and he needed the 6oz 4 times while he was growing more

Could you try him with a dose of Calpol at least 30 minutes before the next feed and see if that helps? If he drinks more, that shoukd answer your worries about his throat