I would definately contact a trainer but make sure it is someone who has experience and/or a degree in animal behavior. There are different types of agression - fear, dominance, etc. and also it may not necessarily be agression. Someone who specializes in animal behavior would be able to pick up subtle signs you may miss. For example, you wouldn't want to "correct" a dog who has fear agression - it will make them more fearful. Even if you have to travel you may only need to travel once or twice for an evaluation and then the trainer can give you things to work on at home. Good luck!!
