Not only can all mammals suck from birth but also sucking has nothing to do with lungs… it uses muscles in the mouth.

What about a platypus? Wikipedia says they lap the milk from grooves in the mother’s abdomen where the milk pools, but this is not really “sucking”, IMHO.

I wonder if the downward flick is more to do with eyes than noses. The wolf in the wild needs to be able to see while it drinks otherwise it would be vulnerable to attack… no good if you have to close them to drink?

All mammals can suck from birth – think about it.

When we suck we use our tongues as a pump, so we can breathe at the same time.

I am not sure that dogs can hold their breath, but as they can swim and hunt in water, I suspect they can.

This is one reason some scientists suspect that humans are actually evolved to fish and swim (aquatic apes) rather than hunt on the prairie as in traditional explanations.

Sucking requires breathing control, you have to use your lungs to suck in liquids and sometimes solids and then redirect them into the digestive tract… dangerous. Thank Darwin for coughing then.