There was a discussion on the FB group some time back & I gave this a little bit of thought before I got busy & discarded it. Attributes, skills & specialties for dogs would accurately model how dogs learn & work, but it's just too complex. I think it best to allow a single specialty such as explosives detection, etc. and leave it at that.
The thing is, trained dogs are very good at their specialties. Way better than the normal task system allows. It's not a +1 to the human handler's skill. If you set a detection dog to work, it will very likely find the thing it is trained to detect, unless the thing is not there. The downside is the dog needs continual training to maintain that level of skill. And dog skills are very narrow. They only react to the things they're trained to react to.