Getting a second dog can be double joy or double trouble. Sibling rivalry aggression or other behavioural problems may arise when a second dog joins your household. Research has shown that inter-dog aggression in a household is much more likely with littermates, particularly of the same sex. If you already have a male dog, consider getting a second dog that is female and vice versa. A good time to get a second dog is when the first dog is well socialised and properly trained in manners and household etiquette. Your second dog will still need dog training, take your new dog separately to training classes that uses positive reinforcement techniques to teach your dog good manners and how to walk on a loose lead. The second dog needs to experience independence and learn home alone gradually, once the new dog has settled in, to avoid ‘second dog syndrome’ take the second dog out alone for a walk and leave it at home by itself at every opportunity. Animal Behaviourist Dr Joanne Righetti, Pet Problem Solved says the biggest mistake people make is expecting pets to get along quickly, friendships take time, it can take several weeks with gradual supervised interactions on leads before you progress to supervised interaction off lead and finally being left on their own together without hurting each other.