Creatine and creatinine contents in different diet types for dogs – effects of source and processing

Summary The concentrations of creatine and its degradation product creatinine were determined in a variety of unprocessed as well as processed feedstuffs suitable for dogs. Unprocessed feedstuffs were categorised as single feedstuffs, bone and raw food diets ( BARF ), and small vertebrates, for example prey animals. Processed feedstuffs were categorised as meat/meat and bone meals, complete wet diets and complete dry diets. The feedstuffs were chosen to cover a broad range of each of the three defined processed and unprocessed feed categories available on the market without further subclustering. The creatine content of the samples was compared on a dry matter, protein and energy basis. The relation of creatine to crude protein permitted a rating of the meat quality in terms of muscle tissue. Results: We found no difference in creatine concentrations between the three categories of unprocessed feedstuffs (raw single feedstuffs, prey and BARF diets), neither on a dry matter basis nor when expressed relative to crude protein and metabolisable energy respectively. Significantly lower levels were determined in meat/meat and bone meal and commercial dry diets (e.g. 303 mg creatine/ MJ ME in unprocessed vs. 6 mg/ MJ ME in processed feedstuffs; p < 0.001). We conclude that in relation to ME , the exclusive use of conventionally processed diets for dogs, especially dry diets, leads to considerably lower intake of creatine which is a natural compound of the diet of this carnivorous and omnivorous species.