In our study, BChE did not differ between obese and lean dogs and was not affected by caloric restriction, in contrast with previous research in canine obesity; in fact, higher BChE activity was assessed in dogs with obesity-related metabolic dysfunction and in those where obesity was induced (Tvarijonaviciute et al., 2010, 2019); moreover, a significant decrease of this enzyme was observed in dogs that experienced rapid, short-term weight loss (Tvarijonaviciute et al., 2013). Here, BCHE is linked to obesity due to melanocortin 4 receptor deficiency.