Dressing for the dog show is like dressing for a date -- you want to respect the occasion without being too matchy-matchy. By adhering to the typical dog show decorum while complementing your pet, you set yourselves up for success.
Following the Rules
Foremost, follow the rules for your dog show. Some dog shows set explicit guidelines for what is and isn't acceptable. Neglecting to do your homework could lead to a run-in with the fashion police. When you sign up for your dog show, inquire whether it imposes rules or guidelines for handler outfits. If they don't, that doesn't mean you can wear anything you want -- just that you have more wiggle room.
Formal and Functional
Dog shows are formal competitions, so even if your show doesn't impose specific rules, respect the show's level of decorum. Ideally, your outfit should be a combination of formality and functionality -- the dog show does, after all, require high mobility on your part. You'll be bending over, walking briskly and handling your dog. You also need a place on your person to hold small motivational treats and a brush for last-minute coat touch-ups. Practicality is just as important as looks.
Your outfit should complement your dog, so choose colors that complement his coat without exactly matching him. If you have a white dog and you wear white, for example, his coat will blend in with your outfit and he won't look as distinct. Alternatively, if your white dog is prone to shedding and you wear black, his fur will noticeably adhere to your clothing. Complementary colors ensure that you match without causing any problems.
While you and your show dog are a team, he's the one the judges are focused on -- so don't choose an outfit that distracts from your dog in any way. Clothing that is too revealing, for example, may take the focus away from the star. Similarly, ostentatious accessories like jangling jewelry cause unwelcome distractions that can interfere with your dog's performance and the judges' attentiveness. While you should take pride in your appearance, a conservative, modest outfit keeps the focus on your dog.