We recommend that puppies start training as early as possible to ensure proper puppy development. We train dogs of all ages and start as young as 8 weeks! Older dogs can learn too! Please keep in mind that service/assistance work can be tiring for dogs especially as dogs approach mid-life. We do not recommend starting with a dog older than about 4 years old, depending on the breed. For dogs that will be trained in any type of scent detection work, we recommend that training starts with a dog younger than 1-year-old.