Metabolic Differences between Dogs of Different Body Sizes

Abstract

Introduction The domesticated dog, Canis lupus familiaris, has been selectively bred to produce extreme diversity in phenotype and genotype. Dogs have an immense diversity in weight and height. Specific differences in metabolism have not been characterized in small dogs as compared to larger dogs. Objectives This study aims to identify metabolic, clinical, and microbiota differences between small and larger dogs. Methods Gas chromatography/mass spectrometry, liquid chromatography/tandem mass spectrometry, clinical chemistry analysis, dual-energy X-ray absorptiometry, and 16S pyrosequencing were used to characterize blood metabolic, clinical, and fecal microbiome systems, respectively. Eighty-three canines from seven different breeds, fed the same kibble diet for 5 weeks, were used in the study. Results 449 metabolites, 16 clinical parameters, and 6 bacteria (at the genus level) were significantly different between small and larger dogs. Hierarchical clustering of the metabolites yielded 8 modules associated with small dog size. ConclusionSmall dogs had a lower antioxidant status and differences in circulating amino acids. Some of the amino acid differences could be attributed to differences in microflora. Additionally, analysis of small dog metabolites and clinical parameters reflected a network which strongly associates with kidney function.

Alterations in serum amino acid concentrations in dogs with protein‐losing enteropathy

“…Unfortunately, because of the small number of control dogs used, we were unable to breed‐match them to the PLE group. Although a recent study documented no statistically significant changes in blood tryptophan concentrations between small and larger dogs, further studies should focus on a breed‐matched control group to remove any possible confounding effects from breed variation. Although the role of prolonged freezing on serum amino acids in dogs is also unknown, the dogs in the apparently healthy group had serum stored in −20°C over a similar time period as dogs in the PLE group and none of the remaining 29 amino acids were shown to be significantly different between the 2 groups.…”

“…22,23 Another important limitation of our study includes the absence of published reference ranges for serum amino acids in dogs. Serum was chosen to measure 24 further studies should focus on a breed-matched control group to remove any possible confounding effects from breed variation.…”

Short-term determination and long-term evaluation of the dietary methionine requirement in adult dogs

“…Secondly, methionine is able to be recycled and salvaged from different pathways, with some dependency on/crosstalk between resources, such as folate or choline (39)(40)(41) . Thirdly, the physiological demands for products of SAA may alter with age, breed, immune needs, physical activity level and diet composition (42,43) . For example, reports indicate that components found in some commercial diets may result in an increased requirement for dietary SAA to reduce the risk of DCM (14,44) .…”

Tryptophan metabolism is differently regulated between large and small dogs

“…Previous research has suggested that individual dog breeds show different metabolomic profiles (Lloyd et al 2016;Nicholatos et al 2019;Viant et al 2007) and that metabolomic profiles change in response to diet and obesity (Forster et al 2018;Soder et al 2017), as well as with specific diseases (e.g., Gookin et al 2018;Hasegawa et al 2014;Minamoto et al 2015). Dogs of varying sizes have been shown to have different levels of circulating amino acids (Middleton et al 2017), as well as different metabolomic profiles (Nicholatos et al 2019).…”