Refusing bottle

Chloe

So my 3 month has always been bottle fed. And always slept really well since about 5 weeks waking up only once in the night. However the past few days she barely wants to eat anything and isn’t sleeping well. She already has bigger teats on her bottle so it’s not that. I don’t know what to do she will only drink 2-3oz at a time whereas normally she will guzzle 4-5oz. She just seems completely uninterested in having a bottle. any advice??