My 5mth old boy could actually drink 150ml of milk every 3hrs. But starting from last week, he only drinks 30-50ml. Now he is sneezing and hving cough, he is still drinking 30-50ml every 3hrs. I have changed the teats already.Is tiz part of teething?

5 months old is a little early to be teething. Teething usually occurs at about 6 months onwards. Nevertheless, i would not rule that out. However, you mentioned your boy having cough, he is unwell. Babies who are unwell take less fluid. Most importantly ensure that he is hydrated. As long as he is still drinking, diapers are wet, id say still pretty safe. Infant cough, best not to give medicine. You just got to let it run its own course. Moniter his liquid intake, and if more symtoms occur please take him to the doctors. Most of the time if they have cough, high chance they will have flu as well. Cough and flu runs concurrently.