To stop a dog from jumping on strangers at a park, you can use a longline, which is a 10m long lead, to keep your dog under control. Clip the longline onto your dog’s harness, and if you see people in the distance, pick up the line and recall your dog back to you. This way your dog is under control and more likely to be able to focus on what you are asking them for. If your dog is getting frustrated and is still jumping up despite being ignored, then you may need to change your approach. Before someone says hello to your dog, try and ask your dog to sit, and ask the person not to give them attention until they do it. When your dog sits, reward them with treats or attention. You can also use treats to encourage your dog to keep all four feet on the floor and divert their attention down instead of leaping up at people. As well as being consistent yourself, you need to ensure that every person who interacts with your dog follows the same rule and ignores your dog’s jumping up behaviour.