The animal known as Hyena is not exactly a dog, although it looks like a dog and like a dog it is a carnivorous. The word Hyena can also be spelt as hyaena. Heyna refers to any of the three species of the coarse-furred, and dog - like carnivorous animals that are usually found in the continents of Asia and Africa and they are noted for their scavenging habits and hunting abilities. The dog – like animals, the Hyenas have kind of long forelegs and they have a very powerful neck and very sturdy shoulders which are of enormous help in dismembering their prey and carrying them. Hyenas are known to be very tireless, determined and diligent trotters and they have excellent sense of sight, extremely acute sense of hearing, and a very strong sense of smell for locating carrion, and they are also very proficient hunters.

These animals are very well known for their hunting skills.
So the answer to your question is that although this animal looks like a dog in many ways, it is essentially not a dog, but a totally different species. Dogs can be tamed and kept as domestic pets while hyenas are totally wild and fierce animals and can be extremely dangerous. You can often see them on national geographic preying on animals as fierce as lions and tigers.