Re: "combo test" - ccr + hddst
No her blood is not checked for the level of the drug in her system. Her vet has never suggested it and I've never asked for it. It helps her breath and that is all that really matters. Nothing I read about it recommends doing that either.
In the US, we don't typically determine the dose of meds we use ourselves - that is left up to the professionals. But I realize things are different where you are so if you decide to increase her dose I would do so slowly. Start at the lower end of the recommended dose then increase if needed. Give her plenty of time on each dose to see if it will help. The cough med, the Gauifenesin, helps a great deal too so if you have that available ask her vet about it. It works to decrease the mucus buildup.
"May you know that absence is full of tender presence and that nothing is ever lost or forgotten." John O'Donahue, "Eternal Echoes"
Death is not a changing of worlds as most imagine, as much as the walls of this world infinitely expanding.