The Kennel are an attack dog training structure in Red Alert 1.
During the Second World War, in order to guard their complexes from spies, the Soviets trained and kept attack dogs. In order to sustain their population, specialized structures called kennels were constructed. The kennel was the place where, when not on duty, dogs could rest and eat before their next assignment as well as where Soviet trainers could train their dogs.
Attack dogs is still used in the Third World War, although kennels were no longer needed; the dogs were trained in the barracks.
It looks like a dog house but just larger.
It was only used to train attack dog. Multiple kennels will reduce the time required to train new dogs.