Chicken and Turkey Vascular Endothelial Growth Factor A (VEGF-A) is a member of the vascular endothelial growth factor (VEGF) family, which includes VEGF-A, VEGF-B, VEGF-C, VEGF-D, and placental growth factor (PlGF)—key regulators of angiogenesis, vascular development, and endothelial cell function. In both chickens (Gallus gallus) and turkeys (Meleagris gallopavo), the VEGF-A protein is identical at the amino acid level, indicating strong evolutionary conservation and suggesting similar biological roles across these avian species. VEGF-A is produced by a variety of cells including endothelial cells, epithelial cells, fibroblasts, macrophages, and developing embryonic tissues, particularly under conditions of hypoxia, growth, or tissue injury. VEGF-A exerts its biological effects primarily through binding to VEGF receptor-1 (VEGFR-1/Flt-1) and VEGF receptor-2 (VEGFR-2/KDR) on endothelial cells, activating intracellular signaling pathways such as MAPK/ERK, PI3K/AKT, and PLCγ, which stimulate endothelial cell proliferation, migration, vascular permeability, and new blood vessel formation. In poultry, VEGF-A plays important roles in embryonic vascular development, growth of rapidly developing tissues, wound healing, and regulation of vascularization in organs such as the skin and reproductive tract. Because vascular development is essential for embryogenesis, tissue growth, and reproductive function in poultry, chicken and turkey VEGF-A are studied in avian developmental biology, vascular physiology, and poultry production research, contributing to understanding of angiogenic signaling in birds.