Coughing dog

My nova scotia duck tolling retriever has been coughing on and off for years.  Sometimes it brings up phlegm; other times not. We know she has allergies to ragweed, grass, weeds, flaxseed.  Her food contains nothing that she's allergic to.  I understand that her allergies may act up in the summer, but her coughing is year-round (we live where we have winter from Nov.-Mar. so the grasses are dead part of the year).  They have diagnosed her with pneumonia and found a shady spot on her lung (our vet thinks this may be scar tissue from a previous bout of pneumonia).  We got her from a shelter (a stray), so we do not know her background. Any suggestions on holistic remedies I can try, or other recommendations of what to consider?  She also has frequent infections in one ear.  Thank you!!

[seattlemom2plus]

I do on occasion put echinacea in our pets food to help them clear up an infection but this would not be helpful if your pet is allergic to weeds of some sort which you mentioned.  Wonder if there is a different allergy that she might have that is causing such irritation.  Keep us posted I am definitely curious on what works for you.