Q. I adopted a dog from a shelter and after 3 weeks my other dog ( boxer ) 8years old has horrible Hacking cough. The new dog doesn't have it at all
A. This may or may not be related to your adoption of the new dog. Kennel cough is a definite possibility, but since the new dog isn't coughing, I'm not as suspicious of that. Older dogs can develop cardiac or pulmonary conditions that have coughing as a symptom, heartworm disease also will cause coughing. Upper respiratory infection and airborne irritants are also possibilities. I recommend getting your dog checked by your vet as soon as possible, an exam and x-rays most likely.