Jekyll & Hyde behavior

Question
Hi,

One week ago we adopted a 14 week old puppy, he is a Shih Tzu/Maltese mix.  We got him from a family that had him since he was 8 weeks old and couldn't deal with having a puppy.  The first 4 days he was an absolute joy!  He was sweet, playful & cuddly. He would try to bite our fingers in a playful puppy way, so we firmly told him "no biting" and moved our hands away. On day 5 the puppy was laying on my sons bed. I went to move him off and he "lost it". He attacked my hand, he had this glazed over look in his eyes and would not stop.  We tried to get him loose but he was going crazy growling and shaking (and doing some good damage to my hand). I finally pried him loose and shrieked at him of course. That day I took him to the Vet, I asked him about this behavior and the Vet said "we all have bad moods".  The Vet checked him out and gave him his shots.  That night the puppy went crazy again.  If we tried to touch him, pet him or pick him up he would lunge and snap at us. He would frantically chase his tale and then run at us barking, snapping, and growling all with this vicious, angry look.  We gave him toys to chew on but nothing would calm him down or distract him.  I finally put on some oven mitts, picked him up and put him in his kennel (I thought it might be pain related from the shots).  During the days he is much better, he plays, he's good with our kids AND the neighborhood kids, he lets us hold him (trying to bite only playfully)... But each evening he starts up again with the same aggressive behavior.  We praise him TONS when he is calm, gentle and playing nicely and we have been firm with him when he has been aggressive. He gets walked everyday and played with for hours (fetch and chase usually), but he is still having these "fits". It is breaking my heart!  Please, any advice would be so helpful.  Thank You!

P.S.  I am a stay-at-home mom and with the puppy constantly.  I always watch him when he is with the kids(for his protection as well as theirs).

Answer
Wow! Sounds like your pup has some serious issues.

If your vet dismissed the problem so easily, I suggest finding a second opinion. Maybe even a third! Another vet may do a more thorough examination, and realize that there are underlying problems causing this behavior.

First off, I suggest you take a notepad and write down a few things each day.
Like, for example, what time he acts up. How long it takes him to settle down. etc..! See if you can get a pattern going, and each day about ten minutes before he acts up, put him in his kennel.

I think it's the fact that he's still under a lot of stress. A new family, new home, new lifestyle in general! Plus with all these people holding him and playing with him, he probably doesn't know what to think. I suggest giving him some alone time everyday... thirty minutes alone in his kennel to relax. If you play with him, make sure he has breaks! To take some of the stress away.

Also make sure he gets a full nights sleep :) Sleep deprivation can cause a number of problems, including aggression, misbehavior, or even biting due to anger and frustration.

So, hopefully all will clear up if you take appropriate action.... If there are other complications, feel free to write a follow up:)
Thanks for your question...
SC