Hi, cilento, I'll bet you're counting the minutes now.
I don't know where on the meseta you're starting, but I don't think you'll be alone even if you want to be! I have never had a problem on the
Camino Frances with dogs, and a bite in my childhood that required surgery to repair has left me with a bit of dog anxiety, so I would remember an incident.
I've been told by many Europeans that the EU has imposed pretty stringent penalties on dog owners whose dogs bite (if anyone bothers to report it, that is), so I think that the huge numbers of people on the Frances has prompted owners to make sure their dogs are confined.
And I agree with others that starting on the meseta is a fine idea. I personally love those wide open spaces with big skies and no obstruction in any direction, but others find it boring. Too much sun might be the biggest drawback, but hat, sunscreen, and lots of water will fix that.
Buen camino to you, hope it's a great one. Laurie