Playing around with other Race Types such as 'UniqueOther' yielded nothing better. However, this variant of Dogmeat does not seem to have any usage animations, and cannot even interact with anything, let alone disarm/plant mines. Setting the 'Race Type' to 'Wolf' forces Dogmeat to use the 'Wolf.spr' sprite, which can be colored to look more like a German Shepard (in line with Fallout 4's version). He can disarm mines with a usage animation (scratching with his hind leg), but if given a mine from another recruit, he is unable to plant it. Setting the 'Race Type' to 'Dog' forces Dogmeat to use the 'MutantDog.spr' sprite.
I've been playing around with a custom Dogmeat recruit for the original campaign (using Redux 1.3), and I've noticed a few things:
