my 14 year old yorkie tye also has the same problem.
hes been on steroids for over 2 years and heart meds for over a year now.
i see in his meds hes given aminophylline, tye has a steroid to help with the coughing but cos of this he cant have his arthritis meds as the two dont mix so i may ask about aminophylline.
glad your little one is doing so well