Why do dogs act strange towards other puppies/kittens

[Reconscope]

I observe them doing energenic things to younger animals despite not being their own species. Could be play bow or running around pawing it smelling the individual young.

In other words their brain organization goes haywire (lack of a better word)

 

[Doggyluv]

They are just curious and trying to figure whatever the thing is out. I know puppies let off a pheromone that tells dogs that they are puppies.

 

[knotme0820]

It’s individual dogs way of saying hi and either being curious and/or trying to interact with the new creature that is in its presence. My old dog will act to act like geriatric puppy when introduced to a new critter of any sorts, the smaller they are the more she seems to like them and the gentler she will be. My other dog on the other hand could care less about the majority of new creatures in his presence and will grumble or even growl sometimes if it wants to smell him. Introduce a person or kid to him and he will get excited. The other one it’s 50/50 whether she will even say hi to new people

 

[Ktwulph]

When I was a kid my dog for into the habit of sitting on the family cats after they semi bullied him when he was a puppy.