Now it wont possible to leave bottle feed...so do sterilise the bottle and try to stop if possible..

9 yr old ? Must be 9 months . A strict NO to bottle , throw it in dust bin right away . A 9 month old is big enough to eat other semi solid food so what he doesn’t drink milk . Give him kheer , dalia , custard , khichadi , dahi , halua , dal rice, meshed potato , banana , halua etc but NO bottle please .you can see that food cooked in milk like kheer custard banana shake etc will have enough milk which you should be giving to baby at the age of 9 months . If you keep him on milk alone and do not give cereals he will decelop anemia therefore food is more important at this age .

If no other go , sterilization of blottle properly will solve issue ,. May other methods are cup feeding , palada feeds , glass ,