aggressive behavior from my 4 year old male pug to a new 6 month old female pug puppy

Question
We have a 4 year old male pug who has been neutered (at 6 months) and just
2 days ago added a 6 month old girl pug who will be spayed in 3 weeks.  She
was rescued by a friend who brought her to us.  Prior to this we owned a girl
pug who was 9 years old when our male came to live with us.  She tolerated
him and they would snuggle up and sleep together when alone in their room,
but when my husband or I came into the picture, jealousy became a problem.  
They would growl and fuss and latch onto each other's necks and roll around
for all the world like they would kill each other.  They never left a mark on
each other, but it was always so stressful for me and my husband.  We lost
our 12  year old pug girl one year ago and our male has been an "only child".
I see in him the aggressiveness toward the  baby girl now when I have one of
them in my lap and the other wants on.  She will share , he will not.  Other
people seem to meld their pets well.  What is wrong with us?

Answer
The problem may not be you but your pug boy. Some dogs just do not play well with others. Sounds like your pug son is very jealous.

Dogs have a pack order. They decide between them who is the alpha. If they decide the male is the alpha in the pack then you must always greet him first, feed him first, etc.

We quite frequently have had this same problem. Right now though, with 21 pugs in the house, everyone gets along remarkably well. To break up fights, we keep spray bottles with water in them strategically placed throughout the house. But anytime they are aggressive to one another, you have to pull them apart to keep them from harming each other, especially the eyes.

Your pug boy may just be telling you that he prefers a one pug household.

Also, I know of trainers, the Dog Whisperer is one, that will gently but forcefully hold the aggressive dog down until it quits struggling to show him you are the pack leader. We have tried that here with some success but not 100%.

Also, you need to make sure your little girl is not in heat. That might set him off too.

Good luck. I wish I had a magic answer for you but I don't.