What can you do with a baby who is teething and has lost appetite completely and refused to breastfeed?

Teething may make your baby’s gums sensitive leading to refusal to feed.  You can try and offer the breast as often as you can. You can also express the milk and try and use an alternative way of feeding.  Cuddle your baby often next to your breast to encourage him to feed.  The good news is that in a little while baby will be able to feed comfortably.