When Does A Dogs Fontanelle Close. Yes, it is possible for the open fontanelle to close. 1 cm appears to be the cutoff if a fontanel will close.

If a baby is not getting enough to eat or is suffering from a stomach virus, the front fontanelle may have a “sunken in” appearance that indicates the baby is dehydrated. However, this is expected to close no later than 3 months of age. The posterior fontanelle generally closes 2 to 3 months after birth;