coughing

[yuki]

My 9 months old female started to cough approximately 3 days ago. It's not deep, dry cough. It's like something stock in her throat and she is just trying to clear it. But it's going on all day. She doesn't cough at night, only during the day, especially when she is up walking. I looked in her throat and didn't see anything there. I hate to go again to the vet because we been there recently several time because of her diarrhea. By the way nothing helped with that. I am so worried because my old dog started to cough kind of like that and he died several months later not from cough but from something else. Does anybody's dog has that type of cough? Can I give her some common cold medication? I got her a new prong collar, bigger than she had before? Is it possible that I damaged her throat doing correction during our walk? I didn't pull hard on it. May be couple times but not that hard. I will appreciate your advice. Thanks.