My Border Terrier Holly is behaving very jealous if Lola our Shihtzu has a treat in her mouth, or a toy etc... she will bark and go at her face. Not biting but she will put her mouth around her mouth and not open it until Lola drops it. It started suddenly last year, it is quite scary when she does it. It scares Lola alot and I feel so sorry for her. Holly will then back off and leave Lola alone. They are the best of friends and this is the only time Holly changes from her usual soft as a brush self. Today I was walking Holly and another dog was walking past. Holly started pulling and the other dog barked and jumped at her. Holly then jumped back and wrapped her mouth around the other dogs and wouldn't let go. I felt dreadful, so embarrassed. The owner of the other dog couldn't open Hollys mouth, she was locked tight. I managed to get her off. The other dog then dropped a ball. I realised that was why Holly did it. I apologised, close to tears, it was horrible. The other dog was fine and its owners were lovely and told me not to worry at all. On the way home we passed another dog, again she pulled but they just sniffed and she was fine. How can I stop her being like this. Last year she was jumped on and attacked by another dog, since then she has acted up with jealousy. She is a lovely dog, real sweet heart but this jealousy is horrible. Thankfully it rarely happens but I worry when walking her she will always go for another dog.