Sunscreen for dogs

I’ve been told by my vet, to get sunscreen for my pet,
because they need protection as well.
What factor should be used, I’m a little confused,
still, I suppose that time will tell.


Ok, the job is done, my dog can now go in the sun,
but this one application cost 7 pounds.
If I apply three times a day, it's goodbye payday,
so goodbye dog, I’m off for a few rounds.

Read this article in yahoo, reported by Sky news
http://uk.news.yahoo.com/skynews/20080725/tuk-pets-need-suncream-too-45dbed5.html

What about spiders, snakes and other small pets?