NUCB2 and obesity due to melanocortin 4 receptor deficiency: This review aims to thoroughly examine current research on regulating energy balance in companion animals, emphasizing the clinical application of orexigenic and anorexigenic peptides, including ghrelin, phoenixin (PNX), asprosin, glucagon-like peptide 1 (GLP-1), leptin, and nesfatin-1, in veterinary obesity management.