white gums is usually lack of blood pressure. check for capilary response.
press on his gums with your finger and see how quickly the spot where you apply pressure turns from white to pink again. like when you check yourself for a sunburn.
Is he eating drinking and active or does he seem lethargic and winded?
If you have not had him long enough to tell if this is his normal color, some dogs are simply lighter gummed or have lower blood pressure when at resst, I would get him to the vet fro a blood test. Could have parasite problem or be anemic. better safe than sorry :)
One thing you should get in the practice of, if you think your dog is sick take it's temp. I learned this from having horses and dogs. The first question I get asked when I call the vet is; "What is there temp?" So now I just do it automatically. It is a good indicator if there is infection. If the dog it not acting like it's normal self, it is best to give the vet a call. Then go from there.
He's your friend,your partner,your defender your dog.You are his life,his love,his leader. He will be yours faithful and true to the last beat of his heart.You owe it to him to worthy of such devotion