If this dog was not rescued as a puppy: This is common with rescued dogs. Since there is very rarely any way to tell what the dog has been through many of their behaviors or ticks can be unpredictable. Aggressiveness with other dogs is common if they were rescued from a place with a lot of dogs but not a lot of resources such as space or food. Aggressiveness to specific people can mean they were either harassed or even abused by people who give the dog the same impression as those they are aggressive to now. Of course this is all speculation since the true story of this dog is unknown. But what can you do? Simple, teach it to be less aggressive. Reward it each time it plays friendly with another dog, or greets a person in a friendly manner. Pay attention to exactly what situations it gets aggressive in and common characteristics of the people who upset it. Use this knowledge to also be aware of when you need to be watchful for scared or aggressive behavior.

If this dog was not rescued as a puppy: Unpredictable behaviors are common with rescued dogs. Since there is very rarely any way to tell what the dog has been through many of their behaviors or ticks can be unpredictable. Aggressiveness with other dogs is common if they were rescued from a place with a lot of dogs but not a lot of resources such as space or food. Aggressiveness to specific people can mean they were either harassed or even abused by people who give the dog the same impression as those they are aggressive to now. Of course this is all speculation since the true story of this dog is unknown. But what can you do? Simple, teach it to be less aggressive. Reward it each time it plays friendly with another dog, or greets a person in a friendly manner. Pay attention to exactly what situations it gets aggressive in and common characteristics of the people who upset it. Use this knowledge to also be aware of when you need to be watchful for scared or aggressive behavior.