There are a number of reasons why a dog will show aggression to another dog. Some of the most common causes are fear or a desire to protect their owner. There are unfortunately dogs that are dominant and aggressive and the signs to look out for are a low-range barking snarling, snapping and growling, holding their ears erect and holding their tail high and moving it stiffly from side to side. Aggressive dominant behaviour is not nearly as common as other causes of aggression.
Fear aggression - fear can lead to aggression - a fearful dog will usually tuck its tail between its legs, lick its lips or try to back away but this fear can lead to aggression between unfamiliar dogs. Aggression between dogs can result in injury to dogs and/or to the people trying to separate them.
Lack of socialization – it is of paramount importance that dogs are socialized, as those that have not been socialized with other animals or humans can become fearful in new situations, such as a walk in the park and meeting other dogs, and react aggressively out of fear as they have a fight or flight mentality. For the well-being of your dog the best way to prevent aggression is socialization from an early age. A socialized dog is far less prone to behave aggressively as they are able to react to the world around them in a healthy way. A socialized dog will move toward another dog in a relaxed and calm way, often approaching from the side or along an arc rather than head-on. Sniffing is a huge part of the process, and you should let them do this as it is perfectly normal behaviour whereby they sniff the glands, pheromones and other scents of another dog.
Territorial aggression - our dogs are territorial by nature and that is why they react to other dogs or people coming on to our properties or getting close to you on a walk.
Protectiveness – dogs do have an innate desire to protect their pack and especially their owners. When on a walk if you immediately become tense and anxious when another dog is approaching your dog will pick up on this and react accordingly thinking you need protection from the other dog.
Illness of injury - If your normally placid dog suddenly becomes aggressive to other dogs they may have an injury or an illness so look out for any of these signs.
Dominant behaviour - dogs that display dominant behaviour feel that they must prove they are in charge of a situation and they will try and dominate other dogs and you if you show weakness and are not in control of a situation. Growling, snapping, or biting occurs when they feel their position is being challenged. A dominant aggressive dog will often give no warning before biting. It would be a good idea to try and help such a dog by consulting a dog behaviourist, as they are professionals in their field and know how to help these dogs.
It is always a bit nerve racking when you first take your dog to the park and another dog approaches – stay calm and remember they will want to greet the other dogs. When out for the first time choose a quiet spot and allow your dog to watch the other dogs and if he remains calm get a bit closer if he shows any signs of excitement move back and when he is quiet give him a treat and praise him and continue to do it until you can approach the other dog calmly. Our dogs take their cues from us so it is important for you stay calm and assertive so that your dog knows you are in control of the situation – shouting at them and tugging on their lead will give them the impression that you are joining in and make the situation worse.
There is very little more pleasant than watching your dog romping in a park with other dogs and it is also a social occasion for you as you get to meet and greet the other dog owners.