10 month old Yorkie pup coughing-PLEASE HELP!

My 10 month old Yorkie pup has been acting strange for the past 2 days. My dad took her to get spayed about 2 weeks ago, and this past Saturday we took her on a 3 hour trip with us to go visit my grandma. Later on Sunday evening, when we arrived back home, my pup Tedi began coughing. Not frequently but once every few minutes. Awhile later around bedtime she settled down and kind of seem depressed, which isnt like her because she's usually in a playful mood from morning to bedtime. My dad and I just thought she was tired or she missed my grandma. But the next day she was still coughing, and also later at night she settled down and was acting like she wasnt feeling good. My dad thinks she has a cold, but I'm getting worried. Are these signs of some kind of illness or am I just over-reacting to her reaction of allergies or something? Please help and thank you!

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

It sounds like she may have kennel cough (tracheobronchitis) or other upper respiratory disease.  These are very common diseases.  If she had not been spayed just two weeks ago the upper respiratory disease might have been so mild that you would not have noticed, but since she did undergo major surgery, her immune system may have been a tad weaker than usual.

Please take her to the vet. for diagnosis and treatment.  You are not over reacting.