So I've had my cocker for 7 months now. Hes 11 months old Male named harley. We also have a shih tzu mix breed dog sam hes 8 years old. Sam is fixed, harley is not but going to be soon. Every night we take them for walks and they get a treat afterwards. They've been getting these peanut butter chewie bones. Recently harley has been going after my other dog sam. It only happens around chewie time. Sam eats all of his and sometimes trys to take harleys and that's when it happens. We are afraid he is going to hurt sam. Usually when they fight like this harley just gets on top of sam and they growl and bark and bite but they're also waging their tails. Lately harley has been going after him more and this last time Harley would not get off of sam. We had to turn a vacume on to get his attention off of sam. Harley is not aggressive any other time, he has never bit anyone or been agressive in any way. It's only around chewie time. Is this food guarding? Should we call a behaviorist? I dont want either dog to get hurt and we are desperate at this point. We have been trying to separate them and it's working a bit but I'm asking for some advice