Dogs were four legged intelligent animals that served mainly as companions and or guards. They were closely related to wolves.
“Gorgumoth was the hound of the Vala Mandos who guarded Melkor in the Castle of Lumbi after he...Gorgumoth
“Beorn's dogs, were large, and grey. There was also four of them. They could walk on their hind...Beorn's dogs
“Grip, Fang, and Wolf were the frightening guard dogs of Farmer Maggot. They are fierce when it...Grip, Fang and Wolf
“The Wolfhounds were a pack of hounds that followed Celegorm. The chief of these hounds was Huan.Wolfhound