Stain recommendation

Hi,

I live in South Texas and my cedar deck sees full sun for about 8 hours a day in the summer. I've been using Olympic stain with some success.

However, I have a dog and after about 9-12 months, I've got to re-stain my deck. The stain is worn off in a pattern that looks like long scratches. The dog doesn't scratch the deck, this is from her walking on it. The rest of the deck that she doesn't walk on looks fine and I wouldn't need to refinish.

A few questions:

1. Should I just clean my deck and re-stain the deck with Olympic (leave the old stain on -- it's not peeling).
2. Should I strip and re-stain my deck with a different product?
3. I'd suggest getting rid of the dog, but she's pretty cool and I like her.

Thanks!

Kevin