A. if the coughing started suddenly there is a good chance it's kennel cough (has she been in contact with other dogs?). If she is not getting preventive treatment for heartworm it's also a possibility to consider. Kennel cough is self limiting and usually resolve without treatment within 2 weeks, sometimes it does need treatment when the cough is too bad though. The acne on the chin is probably not related, could be a small infection or an allergic reaction.
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