If you read about taking pictures of dark dogs, you probably can guess what some of the tips are for taking pictures of light dogs...
Like with the dark dogs, the light meter on the camera looks at the average of the entire frame for the exposure, which usually means the background looks great, but your white dog is glowing. You'll want to look for that same little +/- button, but this time, let in less light; so turn it to the - side. If you set it correctly, you'll end up with good detail on your dog and a nice dark background for contrast.
Many cameras have a "snow" setting, this is generally used for taking pictures of people or objects in the snow - meaning darker objects against a very bright background... the opposite of the problem here.
If you are taking a picture of your white dog playing in the snow, you will actually probably NOT need to use the snow setting because that setting lets in more light - which will likely make both your dog and the background disappear.
All that said, different cameras have different "smart metering" functions so do some experimenting!!! It's not like you're wasting film
Many cameras also have a place to save custom settings, I highly recommend playing with your camera a little and saving the settings that work for your dog - because when you get a chance for "just the right picture" you don't want to have to fuss with settings and try to experiment!