Staying at a Spanish campsite with a dog

In September I am looking to take the plunge and travel to Spain and move around a few sites. I will be taking my Labrador dog with me and wonder what to expect from other other people using the sites and the sites themselves. I have read some reviews from people with dogs using Spanish campsites and so far it does not look that good. Could anyone please tell of any experences good or bad and point me to any sites that are dog friendly.