The resulting frustration translates into increased excitement and agitation, which can be alarming to the owner, who may then deliberately restrict access, tense up before encounters or even punish the dog. This starts an association between the sight of dogs and frustration as well as owner tension and possibly punishment. This, combined with owner-proximity induced resource guarding, is why so many dogs are more aggressive on leash than off. Part of the solution is recognizing the inherently abnormal situation of dogs meeting novel dogs without freedom of movement. Dogs compete for resources such as food, bones, toys, owner attention and sleeping spots and have individual preferences and moods.
Many dogs are also sensitive about proximity and body-contact.
If the fights are damaging to either participant, efforts must be much stricter, with an airtight management regime usually being necessary. The solution, as usual, lies in correct diagnosis and intervention. The penalty must be given every time the dog starts bullying if the behavior is to be affected. If dogs are strong resource guarders, this can be ascertained and managed. If dogs are undersocialized, their confidence can be gradually built up with careful planning.