Hey i have a bitch and she just gave birth to 6 pups. 3 of them are breastfeeding while the other 3 are not they just lick her teats, I'm feeding them beaphar lactol milk replacer. My concern is the ones on milk replacer aren't growing like the others. Help me  what should i do they're 10 days old.

Have you checked there is nothing wrong with the puppies like cleth pallets?

As you said in another post that they have cleft palates, the kindest thing would be to humanely put them to sleep.

And also to think about why half a litter have cleft palates.  That's quite a large number and suggests something genetic going on...