In this report, a clinical case of dietary hyperthyroidism in a dog is described. An elevenmonth-old, male, intact Rottweiler was presented because of panting, weight loss and increasedserum total thyroxine concentration. A complete history revealed that the dog was fed a boneand raw food diet, which made dietary induced hyperthyroidism very likely. Other possible differentialswere excluded after a thorough diagnostic work-up. Finally, after changing towardsa traditional commercial maintenance diet, the clinical symptoms resolved and thyroid bloodvalues normalized. In every dog with an increased serum total thyroxine concentration, with orwithout clinical signs of hyperthyroidism, a thorough dietary history should be obtained. Ownersshould be informed that raw food diets tend to be nutritionally imbalanced, carry the riskof bacterial contamination, and have other safety problems. Therefore, veterinarians shouldrecommend against feeding these diets.