
Hi,
I'm really glad Sensei made it - he had such a rough start to his life he must be a terrific character! One of the first dogs I remember from when I was a little girl was a Peke, and she was gorgeous! I've always had a soft spot for them. Pugs too.
Re the neutering - personally I would wait until they are about 8 months, or maybe 9 or 10 months. My vet books say that early neutering in dogs as well as bitches can lead to incontinence problems in adulthood, so certainly wait until they are mature. Until the new one has properly settled in (it will take at least a month) you won't know which is likely to be the dominant one - Toto is completely out of his depth and insecure at the moment, so may be pushing himself forward more than he would in his 'old' home.
Give them time. Neither is likely to hurt the other. All pups have squabbles, just like human siblings - it's generally all noise and is insignificant. Just keep an eye out to stop things if they look like they may get out of hand, which is
extremely unlikely. Make sure both pups have their own space they can retire to and sulk!
What will Sensei eat now? And how is Toto eating?