Thanks everyone for your answer. I'm afraid it's collapsed trachea
I went to 3 vets, one said it's Kennel cough( he was the first vet who I went to when I just bought my puppy and I though that cough will go away soon), another two don't say anything, I'm tired to go to vet and just spend money for nothing. They just giving me another dose of antibiotic( every time different because of antibiotic resistance I'm already know that too) I'm reading a lot of information on the internet and books ,sometimes I feel like I know more than vet, but still can not help my dog. If it's collapsed trachea, I believe she needs surgery, and it depends what part of the trachea affected, If the only abnormal part is that segment between the throat and the point where the trachea enters the chest (the thoracic inlet), surgery may be curative. However, if the segment of the trachea that is within the chest cavity is abnormal, surgery is not likely to be helpful because that part is not accessible to the surgeon. Endoscopy is the way to visualize the trachea and I know it's very expensive procedure.But right now she still on antibiotic and all other medication and nebulezer, I'll see how she will feel by the time when antibiotic will finished.
LUZANGELA428, I bought my puppy not from the breeder
and have no idea about other puppy in the litter. That's why I have nobody to help me :-( I bought
http://www.puppypetite.com/yorkies.html that's in New York, they have only 2 weeks refund policy, but I have problem with the dog since the time I bought her, I thought the cough will go away, and I'm in love with my dog, I don't know what to do