My dog is acting weird

I have a maltese poodle mix and she has started acting really wierd.she will not leave my side or my kids side at all.Her ears are back and her tail is down shes acting nervous.she looks back and fourth like she is looking for something.she dont stay still long at all.I'm kinda scared.She is kinda ok when im holding her.

[Aleda M Cheng, D.V.M., C.V.A]

Could you give me more details?  

How long has this been going on?  
When did it start?  
Did it start at Halloween when lots of strangers came to the house for trick or treat?  Has anything changed in the environment?  
Has anyone taken care of her who may have caused her to become fearful?  
How old is she?  
Is she spayed?
Have you moved recently?
Has she ever exhibited this behavior before?
Please list anything else that you think may be pertinent.

Though Dr. Dan or I would be pleased to try to help you, please realize that it would be a good idea to take her to the vet to have this problem resolved promptly.

[BJ78]

Its only been the last 2 days.We didn't have anyone come to the house for halloween we take our kids out.Shes always with us.No big changes this is why I dont know whats going on with her.Shes 2 years old shes not spayed.Shes always been a little nervous but never like this.I know when she was a puppy the people we got her from broke her tail thats why I think she is always a little nervous.But like I said she is bad now.Last night she threw up a little but hasnt since.

[Aleda M Cheng, D.V.M., C.V.A]

It looks like you really need some professional help then.  You should take her to a vet to determine if there is some physical cause for her behavior, such as a painful back, for example.  If there is no physical cause, maybe your vet can prescribe some behavioral therapy and natural or other tranquilizer.

[mousegirl288]

My dog is acting weird she is spayed and it been going on ever since we got a new dog friday she is 7 months old could this be a sighn of parvo????