WHY DO DOGS FIGHT?
Fighting between dogs of the same sex is common and will occur naturally. Dogs have always fought over food, the right to mate, their position in a pack, and in defence of their young or their territory. Individual dogs vary in their inclination to fight because of their breeding, socialisation, experience and training. Some breeds of dogs and individuals of breeds have been selected for their fighting or guarding qualities, and may be more likely to fight other dogs.
Male dogs will usually fight with each other more than female dogs do, but fights between females are more common when one or both are in season. Dogs that have been well socialised with other dogs from an early age are less likely to fight. This should be done from the very early puppy stages (when the dog is only 6 to 8 weeks old), and should be continued throughout the dogs life.
Aggression between dogs of the same sex does not usually develop until just before, or at sexual maturity. Fights between strange dogs frequently occur when one of the dogs is protecting its territory, its owner, or itself. Dogs on a lead sometimes become very possessive of their owner. Fights can break out between two dogs on a lead passing close by each other, or when two dogs are off lead and their owners are in close proximity.
Owners with aggressive dogs must take particular care when near other dogs. Many dog fights begin because an owner's attention is elsewhere and the dog is not corrected immediately after an incident occurs. What may happen when two dogs meet cannot always be predicted. A normally friendly dog may take a particular dislike to another dog and start a fight with it.
TREATMENT FOR A DOG THAT FIGHTS OTHER DOGS
Castration can reduce fighting in male dogs. This operation changes the odour of the dog, and consequently the other dog's reactions to it. It also reduces the amount of testosterone (the male hormone which precipitates the aggression) that is produced. Female dogs may also be aggressive towards each other, but male/female fights are less common. When the fighting is due to a dog being frightened or protective, castration will have no effect.