The "Download Now" link directs you to the iTunes App Store, where you must continue the download process. You must have iTunes installed in order to open the link, and you must have an active iTunes account to download the application. This download may not be available in some countries.
From KGBTexas .communications:
Your pet is your best friend, and Emergency Pet Center is here to help keep them healthy. My Pet Health Record keeps track of your pets, their health information (e.g., blood type, medications, allergies) and their appointments (e.g., annual vet schedule, heartworm medicine reminders). Plus, in an emergency, we'll get you from your house to one of our convenient locations to ensure your pet is well cared for. For people that love their pets as members of the family, Emergency Pet Center provides the best possible emergency and critical care for companion animals when skill, experience and compassion matter most. We're your best friend in an emergency.