The annual checkup has become routine practice for people, dogs, and cats. One big difference is that pets age as much as seven times faster than people. On average, most dogs and cats reach adulthood by the age of two. By age four, many pets are entering middle age. And by age seven, most dogs, particularly larger breeds, are entering their senior years.
Because dogs and cats age seven times faster than people, significant health changes can occur in a short amount of time. And the risks of cancer, diabetes, obesity, arthritis, heart disease, kidney 
disease, thyroid problems, and other serious conditions all increase with age. Therefore, it is now best for pets to have a wellness exam every six months so that we have the opportunity to detect, treat or ideally, prevent problems before they become life-threatening.