Qualifications for a dog grooming job are optional. While that sounds a bit odd, the truth is that you can get into dog grooming through two vastly different paths. First, let's say you love dogs and want to become a dog groomer, but don't have any experience. You can (1) respond to a Help Wanted ad for a grooming salon bather, which means that's probably what you'll be doing for the foreseeable future. You might eventually grow into a groomer position, but that's to be determined.
Option (2) still assumes you're a dog lover with no experience. You might work in a big box pet supply store's grooming shop or in a larger grooming salon. You'll hire on as a groomer trainee, and will gradually learn to trim nails, bathe and brush dogs, and handle uncomplicated grooms such as single-length cuts or shave-downs. While you might pick up some finer grooming techniques along the way, that's basically a function of how much time experienced groomers have to spend with you.
Now we get to the second path, which involves education, commitment, and money. You'll attend one of 50 state-licensed grooming schools for a period of two to 18 very long weeks. During your training, you'll develop breed recognition skills, which helps you distinguish a cocker spaniel from an Irish springer spaniel. You'll also learn dog handling and bite prevention techniques, first aid and dental care procedures. Oh, by the way, you'll also develop basic grooming skills. You'll probably have to pass a final exam based on standards created by the National Dog Groomers Association of America. Assuming you make it through, you'll receive a diploma or certificate for your grooming station.
Finally, here's an FYI for potential grooming shop or mobile grooming service owners. Some grooming school programs also include business ownership and customer relations coursework.
Once you complete an accredited pet grooming program, you'll be a known quantity to a potential employer. While your basic grooming program might not have covered exacting show grooming techniques, you can certainly acquire that specialized knowledge later in your career. Here's what's important to an employer: you can hit the ground running.