behavior/spaying
 

my yorkie is 7 months old and was spayed about three weeks ago. prior to being spayed she loved going to the local dog park and played with dogs no matter how big they were. today i took her for the first time after spaying and she was shaking from fear. she wouldn't interact with the other dogs at all so i took her right home. does anyone know if this is just temporary or is it a permanant behavioral change. the other thing is that she still loves playing with all of the dogs in the neighborhood.

I dont think their behavior changes after a spaying at all. At least my female didnt. Maybe she just got a littlet uncertain and that is why she shoke. If she interacts with the dogs in your neighborhood just fine. I wish I was as lucky as you my female barks at other dogs.

behaviour/spaying
 

Spaying will not cause a behaviour change like that. Spaying sure never made a difference in any of mine.
Her age at between 6 and 7 months, means she is still a baby. They do not have long memories. SHe likely did not know the dog park anymore if she hadn't been there for three weeks. Also at 6 to 7 months their personalities start developing a little more. She may not be happy there anymore or it is very possible she sensed some sort of danger you were not aware of. Yorkies are very smart and I trust the reactions of my dogs to situations.
Personally, if this is an off leash park, I do not ever recommend taking Yorkies there. Why? I have heard of way too many small breeds of dogs being hurt or killed by large dogs off leash. Yes, I know, the owner of the large dog always absolutely swears that their dog will not hurt your little one. If they are wrong, the large dog is never injured, your little one can be or be killed.
It isn't necessarily that the large dog is mean. What often happens is that instincts kick in and things happen. Dogs will always have instinctual behaviour that can come out at any moment.
Don't set your dog up for a dangerous situation.