I know what you may be thinking, simply search for literally "Male canine", but the problem there is that the "male" trait may not actually belong to the canine himself. For example, a male human and female canine still has the tags male (because of the human) and canine (because of the female canine). Maybe the human is penetrating the female canine, so one could exclude the tag, filtering the results, but then other unwanted results are bound to arise.
Strangely enough, we actually do have a human_male tag, but literally only one post has it, so that wouldn't do the trick.