There are a couple groups of tags that have a general tag that covers a lot of cases, but a few specific subjects are asked about often, so they have also gotten an individual tag.
The clearest case is training. We have training, but we also have tags that cover specific types of training: toilet-training, leash-training, and clicker-training. We could probably reasonably create crate-training.
Another case is health, with a range of tags with various specificity.
And a bunch of things that could go under diseases or injuries:
Some of the questions with the specific tags also have the general tag, some only have the specific tag, and others only have the general tag (while they could have the specific tag). I've tried to add the specific tag where I see it's missing, but I'm not sure if the general tag should also be added or removed.
I believe we should prefer the specific tag where one exists, and leave the general tag for unusual cases/circumstances that don't get asked about very often. However, I can see a case for labeling all of the training questions with training since some of the methods should apply to any training problem.