Barding, if you don't have it already, is priority #1.
Beyond that, anything you'd equip or cast on yourself would be useful. Dog Collar of Invisibility, anyone?
Or maybe "pet" specific items could be created- Dog Booties of Blinking? Dog Tags of Charm Monster?
Or maybe "pet" specific items could be created- Dog Booties of Blinking? Dog Tags of Charm Monster?

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.