How Nutritional Requirements Differ Among Various Working Canines

The exact origin of man’s best friend remains somewhat unclear (Vila et al., 1997; DOI: 10.1126/science.276.5319.1687), however it is accepted that they have co-existed alongside us for more than 14,000 years (Giemsch et al., 2015; Hugo Obermaier Society for Quaternary Research and Archaeology of the Stone Age: 57th Annual Meeting in Heidenheim, 7th – 11th April 2015, 36-37). Human intervention, through selection, has slowly transformed canines to the array of breeds that we know today. Accompanying the development of these breeds and their phenotypic traits are the behavioral traits that contributes to their uniqueness. We currently employ canines to assist with various tasks including detection, guide or service, law enforcement, a plethora of sporting activities, as well as a growing number of additional activities. It is almost a certainty that in the future there will be new activities where we will utilize canine assistance. Working canines, like their species, are extremely diverse in their make as well as their nutritional requirements. Competitive canines are most commonly in the 15-40 kg range, however there are representatives that are greatly different from this range. Just considering the number of breeds and the range in size among working canines, it should not be surprising that the nutritional requirements for this segment would also vary greatly. However, the more intriguing considerations are those nutritional changes dictated by activity level rather than body size. In general terms, most dogs in the working segment possess a neutral environment resting energy requirement of approximately 1300-1400 kcal/day (Hill, 1998. J. Nutri 128(12): 2686S-2690S, Bermingham et al., 2014. PLOS 9(10) e109681). However when we consider the impact of activity, the energy requirements can dramatically change. Consider the racing segment, where the work load on the dog can range from a few hundred meters / day (Sprints) to race distances approaching 200 km /day for endurance sled dogs. Hill (1998) reported on slight increases above resting maintenance energy requirements for racing Greyhounds. In contrast, the energy requirements for endurance sled dogs has been reported to be greater than 11,000 calories per day (Hinchcliff et al., 1997. AM J Vet Res, 58: 1457-62; Loftus et al, 2014. J Nutri Sci, 3: 1-5; DOI:10.1017/jns.2014.31). This review will further examine the impact of activity type and work load on the nutritional requirements of canine athletes as well as the effect specific nutrient class has on performance across multiple segments of working canines.