Driving into Spain from France, whether through the Pyrenees or along the coast, doesn't involve a formal pet document check the way a flight or ferry arrival does, since there's no fixed customs post for pet travel between two Schengen countries. The documentation requirement is the same as any other entry point into Spain: microchip, rabies vaccination, and a valid EU pet passport if you're an EU resident, or a health certificate if you're not.
A single EU pet passport or non-EU health certificate generally covers the whole trip across the Schengen area, so there's no separate Spanish-specific form to arrange just because you're crossing a land border rather than flying in. This is one of the more straightforward routes into the country precisely because it mirrors the same rules covered in the Documents section, with no extra transport-specific layer on top.
The one thing worth checking before a land crossing with a dog that might fall under Spain's PPP system is that the licensing and insurance requirements apply once you're resident or staying in Spain, not at the border itself — so there's no muzzle-and-leash checkpoint on the motorway, but the local registration requirement still applies once you've arrived and are staying somewhere in the country.