Panting, restlessness are often symptoms of pain and/or anxiety in a canine. Best to take him to the vet.
Is he due for a senior workup? Age 7 is a good time to get some lab work and a physical.
If you haven’t been brushing his teeth daily he may very well need a professional cleaning and extractions.
PS: Be careful with those supplements “natural” does not mean benign and some supplements can cause harm.
Some science-based veterinary medicine information here:
http://skeptvet.com/Blog/category/herbs-and-supplements/
