Whats wrong with my 4 month old pit

yesterday she didnt eat at all and now that i see her she looks really skinny and she dont want to play and her nose is very dry..what do you think is wrong with her??

I am not a vet or a dog expert but... we have 2 APBTs, a 1 year old male and a 4 month old female. When we first got our female (Destiny) she was 8 weeks old. We drove about a hour to pick her up and when we were in the car on the way home she threw up a few times, I just thought she was scared. She was really really skinny! You could see her hip bones and her ribs! :( So, we got her home and tried to feed her but she wouldnt eat.. she wouldnt drink water either! Infact, she really didnt do anything! She just slept and cried! I thought it was because she was in a new home and she was scared!.. Later that day she sneezed a few times and she sounded really stuffed up, so we took her to an emergency vet because I thought she had a cold. After the vet checked her out he said that 1st of all there is no way she is 8 weeks! She has to be about 5-6 weeks old.. 2nd she isnt eating, drinking or doing anything because her red blood cell count is dangerously low! Shes seriously dehyderated and she also has fleas and almost every kind of worm a dog can get! He said that if we wouldnt have brought her in when we did she most likely would have died! :( OMG! I freaked out! They said that they would have to give her a blood transfusion and give her some fluids and meds through an IV. They said they would have to keep her for a few days and they couldnt tell us if she was going to live or not! -Remember, this is the 1st day we got her! Thats alot to handel on the first day!- Wow! That was such a horrible thing to have to go throught! I was crying and that is one of the few times I have seen my husband cry!.. So anyway, she got her blood transfusion and within a day they told us she should be fine, and the next day we went to pick her up! The vet bill set us back about $1,500, but it was worth it! She was like a whole new puppy! lol.. now shes 4 months and doing great!... I didnt tell you all of that to scare you lol.. the only reason she got so bad was because she was so young and the idiots we got her from didnt take care of her!.. and I am not saying she has what Destiny did, like I said to start with, I am not a vet or a dog expert by any means! lol.. but I would suggest taking her to the vet. If she isnt eating and she looks skinny, it might be something serious!.. Good luck! I hope everything works out! : )