Bloodwork is recommended yearly for many reasons. Vets can use baseline values to determine if a problem is lurking and start treatment. Your pet may look and act perfectly healthy, but bloodwork may tell the vet something different. Many problems, if detected early and before the pet is showing clinical signs, may be treated more effectively. If sick, bloodwork results can be compared to hopefully determine the problem. Instead of just having one set of numbers where vets say, "Is this normal for the pet or not," there are many values so vets know what is and is not normal for that animal. Bloodwork also tells vets what meds to or to not give and what anesthesia to or to not use. I do bloodwork on my pets every year starting when they are adopted regardless of age and every 6 months on my seniors. So, Why is Preanesthetic Bloodwork Necessary? For DOGS, CATS? Why is Bloodwork Necessary? Can Testing Uncover Hidden Health Problems in DOGS and CATS? How can you understand Bloodwork and Urine? What are the common questions you may have?