I have a golden retriever, 3yrs. who is 8lbs. Overweight, doesn't seem to have much energy. Eating a lot of grass and pants hard all the time. Travels with us a lot.

When was his last vet check?

Overweight dogs are prone to diebetes.

Eating grass indicates an upset stomach.

Sounds like overfeeding at first read. The grass is used to induce vomiting, as Shaz says, due to a tummy upset. A 3y.o. Golden should need about a cup and a half of (dry) food per day if they're not very active, like when traveling.

Consider getting his thyroid checked at his next vet visit.

One symptom of thyroid disorder in dogs is dry flaky skin, it looks like dander but worse.

I agree that you should get him checked for this disorder as it can be treated by daily medication.

How often do you walk your dog? Is he lazy or just not excercised enough?

As for the grass eating, dogs are amazing. As Shaz and Catsmine said dogs eat grass to settle an upset tummy or to provoke vomitting because of something they ate.

Time for a vet visit. :)