A guard dog training school is only as good as its team of guard dog trainers. If you want to get your dog into a good school, you need to first and foremost look for qualified and certified dog trainers under the school's list of employees. A good guard dog training school might be precious, but a very good guard dog trainer is golden.
The path to becoming a professional guard dog trainer is easy, albeit a bit confusing. It's like, “Which course should I take in college if I wanted to become an astronaut?” or something like that.
Becoming a professional guard dog trainer begins and ends with a love for animals in general, and dogs in particular. Anyone can set up shop and become a guard dog trainer. But if you want to leave away the technicalities, you only need a broad and diverse knowledge of everything important to the training of guard dogs, a good place to do the training in, and a proud list of seminars about the modern ways of guard dog training under his or her belt. In this regard, anyone can become a guard dog trainer.
But if you want something concrete, some sort of formal education to back you up as a professional guard dog trainer, there are a few fields of study that are proven useful in this line of work.
An animal behaviorist is one. If you're going to be working with animals, it doesn't hurt to learn about their behaviors and mannerisms from a scientific point of view, right? The field is dedicated to understanding the functions, development, causes and evolution of animal behavior, including dogs. Knowledge in the field of study that is animal behavior is one of those rare things that can't possibly hurt you as a guard dog trainer.
After getting a degree, it's time for you to either set up your own shop or find work as a guard dog trainer in a training school. The second option is good, too. But nobody wants to work for somebody forever. Hopefully, in the future, with enough experience, you'd find the courage to take care of the dogs yourself through your own dog training school.