It depends. If your dog is human aggressive, then the answer is no. The safety of our walkers is a very high concern for us, so we can't knowingly put our walkers into a dangerous situation. This is even more true when a substitute is required who may not have a chance to meet the dog prior to their visit. If your dog is aggressive only toward other dogs, we may still be able to help out. During our initial meeting, we would make sure that our walkers would be able to keep control of any situations that could arise. If you have a 120 pound dog that charges after any other dog in its path, then we probably can't help you!