Dogman is something fairly new to popular culture's dialogue, but these mysterious figures have been reported as far as back as man had written language and cave art. Said to walk on its hind legs, have the snout of a dog and the ears, as well as long canines and fur covering its body, most would call them werewolves, but there are many possible explanations and theories as to what Dogman is.
Werewolf: Early on in explanations of Dogman, werewolf was one of two explanations on the table including misunderstood natural animal. It's interesting because the concept of a man turning to wolf, although very romantically appealing, is a highly illogical conclusion. But, if put into the category of fairies and trolls, it could be enjoyed with a sense of adventure without any threat in the "real world." It could be appreciated like the Jackals of old portrayed in ancient art; a mythical being, a symbol of how close man is from being a beast versus civilized.
Shapeshifter: A shapeshifter would have a spiritual origin. This would involve a form of magic that allows the sorcerer/magician/shaman to change physical form and represent himself as another creature. The fact that it walks on two legs but has chimera aspects of a dog and that it is very rarely seen even though there would need to be a breeding population, makes shapeshifter high on the differential.
Variation of Bigfoot: I have heard this concept from a few people in the Bigfoot community who have interviewed enough witnesses to wonder if perhaps there are variations of Bigfoot that involve longer foreface, more prominent jaw, that creates an almost bear-like snout appearance. The only part of this explanation that isn't quite right are the descriptions of dog-like ears and leaving paw prints behind, as well as a generally shorter height around the 6-foot range.
Misunderstood explainable: People in the woods? A bear? A shape in the shadows? A glimpse of something out of the corner of one's eye? These can explain a good deal of sightings of both Bigfoot and Dogman, but not ALL of them. Some sightings are so up close and personal as to be able to describe the stance, facial features, behavior and walking ability.
Spirit/Demon: Something with long fangs, dog ears and snout, angry and, according to some accounts, able to control your thoughts? That sounds like something evil, right? There are almost no accounts of beneficial encounters with Dogman and with them working so hard NOT to be seen, it would seem that they are antisocial, perhaps even aggressive. Some reports have them attacking farm animals and tearing them to shreds and there are a few legends like the story of Land Between the Lakes in Kentucky that include people being murdered.
Alternate Universe: Where does he go? We're almost never running into him. At some point, we should be coming across their lairs, right? So, why do they appear to leave no traces of their existence in the woods other than the random footprint? Strange lights seen in the woods, odd feelings, memory lapses, and other issues have made people conjecture that these beings coming and go from some kind of portal between worlds.
Alien: Were dogmen sent to earth to terrorize? To control the Bigfoot population? To scavenge? To pilfer? To report back? There are reports of Dogman being able to insert thoughts into a person's mind, remove memories, or put a human voice in their head to move them on to another area in the woods or to not look at them. These qualities would be considered exceptional, even otherworldly.
DNA manipulation: With reports of lizardman, apeman, mothman, and dogman, it would seem an obvious conclusion is that man had been a some time manipulated and mixed with animal DNA to try variations of enhancing certain characteristics. This manipulation would have been done by an advanced culture, i.e. alien.
Unlike Bigfoot, I have not encountered a Dogman, but I have listened to descriptions by those who live in Dogman territory and who have encountered them. There is an understanding among many of them that Dogman is the only thing Bigfoot fears. If this were so, the relationship is an odd one; Dogman is shorter than Bigfoot and surely not as powerful, and yet Bigfoot consider them evil and bad. When I look at the amount of Dogman to the amount of Bigfoot and that they share the same territory, but Bigfoots steer clear of them, I have to say that their relationship would be a bit like a prison guard to Bigfoot on a penal colony. Either that, or Dogman is just an angry being compared to the more quiet and gentle Bigfoot.
Are we talking about a legend, a misunderstood creature, a variant of Bigfoot or something otherworldly, I can't say, but I must admit that Dogman intrigues me even more than Bigfoot because a hairy man is quite possible, but a Dogman is an abomination that seems quite impossible by natural means.
Great resources to learn more about Dogman:
Linda Godfrey Author and researcher who brought Dogman into the forefront of cryptid studies.