The development of a natural model of multiple sclerosis (MS) would be useful for understanding mechanisms of the disease and testing novel therapeutics. Jorge Alvarez, PhD, University of Pennsylvania, Philadelphia, PA, comments on using companion animals with diseases similar to progressive MS, exhibiting central nervous system (CNS) compartmentalized inflammation, as a model for MS in humans. This interview took place at the ACTRIMS Forum 2022 congress in West Palm Beach, Florida.