Background/Objectives: International guidelines advocate for personalized vaccination protocols using point-of-care (POC) antibody titration to identify dogs requiring boosters for CPV-2, CDV, and CAdV-1. As traditional venipuncture can be challenging in specific patients, this study evaluate the clinical agreement of a novel minimally invasive capillary blood sampling technique (ear-prick) for core vaccine antibody titration. Methods: Paired blood samples were collected from 55 healthy dogs using venipuncture and an ear-prick technique with a portable lancet. Antibody titers were determined using a semi-quantitative POC kit (VacciCheck^® Canine). The procedure was optimized comparing 28G and 21G lancets, with the latter used in 43 dogs to ensure adequate blood flow. Comprehensive statistical methods evaluated the correlation and agreement between the two sampling techniques. Results: Statistical analysis showed no significant differences between sampling methods (p > 0.05). In the optimized group (21G lancet), full match rates reached 81.4% for CPV-2, 76.8% for CDV, and 74.4% for CAdV-1. Clinical concordance was exceptionally high: 95.3% for CPV-2, 90.7% for CDV, and 100% for CAdV-1. Statistical analysis confirmed perfect agreement (1.00) for CPV-2 and CAdV-1, and moderate agreement (0.48) for CDV. Conclusions: The ear-prick technique using a 21G lancet is a reliable, minimally invasive alternative to venipuncture for antibody titration. This method simplifies clinical procedures and facilitates personalized immunization monitoring. Given the minimal blood volume required, it represents a versatile approach for evaluating immune status and protection levels to core vaccines in diverse settings, including pediatric and shelter medicine.