The American Canine Association, Inc. ( ACA) is the world's largest health tracking dog registry. ACA sanctions dog shows and competition trials throughout North American and the Caribbean. ACA is the second largest dog registry and was established in 1984. This web page contains contact information such as email, phone number, fax number, and regional office mailing information. Home Page. ACA dog, ACA registered, ACA puppy, ACA vs AKC, ACA vs APRI