I currently have two dogs (one medium and one large) that I have had from 8 weeks to 6.5 years old and 8 weeks to 3 years old. All three of us are very active and I hope to be equally as active with your dog! I have a large SUV so could plan some longer sessions together (hiking, trail running, etc) to accommodate your dogs needs. I prefer to work with higher energy dogs. Large dogs are fine ( I have a 100 lb German Shepherd). Although small dogs are fine as well. I will treat your dog as if they were my own dog. Every dog breed is fine with me as well! Not bias to any type of dog and can work with aggressive dogs as well.