Hello Sir...the picture indicates its starting of cavity or decay.
Since your child is below 2 yrs and it isn't safe now to take to dentist you can do the following steps till now.
1.Avoid breast feeding or bottle feeding in the night in between sleep.if child don't sleep otherwise you can keep a bottle of plain drinking water to give immediately after feeding to avoid milk accumulation around teeth.
2.dont out
sugar in bottle milk,if already doing so kindly start reducing the sugar amount and later stop it completely.
3.if child isn't permitting you to brush two times a day ,u can get clean cloth and wipe off everytime after feeding .
And give water in between to avoid food accumulation.
And meanwhile use finger brush and try to brush .if your child still don't know to spit,no need to use toothpaste and give drinking water to clean mouth
Next Steps
Consult your dentist and decide treatment options for your child
Health Tips
1.avoid
sugar in milk
2.brush or clean teeth with cloth
3.give plain drinking water immediately after feeding