Dog aggression between canine members of a household usually involves dogs of the same sex, often littermates.
Trigger people in the family [Editor: Trigger people?] often stimulate such fights, though sometimes food or another dog may also stimulate fighting.
To avoid such dog fights, it is best not to obtain littermates of the same sex, particularly those that appear competitive within the litter. Also, when a new dog is adopted into the family, it is a good idea to pay more “jolly-type” attention to the resident dog(s) than was shown before the newcomer’s arrival.
Make the additional pet fun for the resident pet. Allow the new animal to fit in and adjust with less attention than is shown the older members. This will cause resident dogs to have pleasant associations with the new animal. If a fight should erupt, never induce more hostility into the situation by shouting, screaming, scolding, hitting, kicking the heads or bodies of the fighters or pulling them apart by the heads or necks.
Most serious canine quibbling seen involves owners who induce hysteria into the original battle, which, if allowed to reach its conclusion naturally (if the owners had left the scene or remained passive), more than likely would have concluded bloodlessly and with one permanently dominant and one submissive dog. The most effective method for stopping a fight requires that someone pick up the more aggressive of the warring pair by the tail, just high enough so its hind feet cannot touch the ground. If both dogs are aggressors, then both must be elevated.
Lack of hindquarter traction often quickly short circuits hostility. If either dog has a docked tail, the hind legs may be picked up to equal advantage. A common underlying cause of persistent fighting is owner hysteria when such fights break out. Most owners of multiple dogs who do not have such problems did not become hysterical when fights or hostilities initially erupted. In more than 95% of sibling-type fighting, the dogs never fought unless the owners were present. A good percentage of them were boarded together in the same run without hostile signs.
This brings us to one type of remedial program that is often successful: boarding the dogs together on neutral territory, there to be visited by the family under controlled conditions after a week or so. If no fight ensues, a daily series of visits, followed by rides in the family car to other neutral areas, will often help if the plan spans 3-6 weeks. After this, a daily trip home can be included. Dogs fighting for any reason must be taught to respond to simple commands to Come, Sit and Stay when the owner directs. All fondling, coddling or solicitous behavior toward the pet must be avoided. This helps the owner assume dominance over the dogs involved and is prerequisite to all procedures recommended.
[Editor’s note: I don’t agree with everything in this article. Parts of it are a bit remedial in suggesting that it is the owner that creates dog on dog aggression, as I’ve seen enough scenarios where one dog gets defensive while being corrected by another dog, and then the fight escalates. This is irrelevent to whether the owner is home or not. In such cases, the dogs should be kenneled separately when the owner is not there to supervise. Also– kenneling at a “neutral territory” is not going to fix dog-on-dog aggression, which is relationship-based at it’s core. What needs to happen is for the pack leader (you) to be present and to correct and instruct both dogs that dog aggression will not be tolerated.]