¹Selçuk University, Faculty of Veterinary Medicine, Department of Animal Nutrition and Nutritional Diseases, TR-42130 Konya - TÜRKİYE
²Atatürk University, Faculty of Veterinary Medicine, Department of Animal Nutrition and Nutritional Diseases, TR-25240 Erzurum - TÜRKİYE
³Selçuk University, Institute of Health Sciences, TR-42130 Konya - TÜRKİYE DOI : 10.9775/kvfd.2026.37699 Methylsulfonylmethane (MSM) is a naturally occurring organosulfur compound whose effects in dogs are poorly characterised. This study evaluated dietary MSM on nutrient digestibility, blood parameters and faecal fermentation in Golden Retriever dogs. Twenty-four healthy adults (2-8 years; 30.7±3.3 kg) were randomly allocated to three groups of eight: a basal diet without MSM (Control) and the same diet top-dressed with 4 g (MSM4; 127 mg/kg) or 8 g (MSM8; 259 mg/kg) MSM per head daily for 30 days. Digestibility (acid-insoluble ash), blood (days 0 and 30) and faecal short-chain fatty acids (SCFA) and ammonia were assessed. Apparent digestibility of dry matter, organic matter, crude protein and crude fat did not differ among groups (P>0.05). Serum glucose and creatinine differed among groups (P<0.01); triglyceride showed only a linear trend (overall P=0.064; linear P=0.026). The relative monocyte proportion rose and the neutrophil proportion fell with dose. Faecal consistency and pH were unchanged, but faecal acetate was lower in MSM8 than in the control (P=0.021), total SCFA declined linearly (P=0.011) and faecal ammonia-N was higher in MSM8 (P=0.014). In this small 30-day study, MSM at 4 or 8 g/head/day was not associated with detectable differences in digestibility or faecal consistency; some clinical-pathology and faecal metabolite measures differed or showed dose trends, but their biological significance is uncertain and the fermentation findings require confirmation. Keywords : Methylsulfonylmethane, Dog, Nutrient digestibility, Blood parameters, Faecal fermentation, Short-chain fatty acids