Changes

In a thermoneutral environment, BMR accounts for approximately 60% of the animal’s total daily energy expenditure, while normal activity is 30%, and dietary thermogenesis accounts for 10% energy utilization<ref>Case LP, et al. In Canine and Feline Nutrition: A resource for Companion Animal Professionals. 2011 Third Ed. St. Louis: Mosby p.59-61.</ref>. Energy expenditure for adaptive thermogenesis varies with temperature, humidity and coat thickness<ref>National Research Council (NRC). Physical Activity and Environment. In Nutrient Requirements for Dogs and Cats. 2006 Washington, DC: National Academies Press p.267-273.</ref>.

In a thermoneutral environment, BMR accounts for approximately 60% of the animal’s total daily energy expenditure, while normal activity is 30%, and dietary thermogenesis accounts for 10% energy utilization<ref>Case LP, et al. In Canine and Feline Nutrition: A resource for Companion Animal Professionals. 2011 Third Ed. St. Louis: Mosby p.59-61.</ref>. Energy expenditure for adaptive thermogenesis varies with temperature, humidity and coat thickness<ref>National Research Council (NRC). Physical Activity and Environment. In Nutrient Requirements for Dogs and Cats. 2006 Washington, DC: National Academies Press p.267-273.</ref>.

'''Resting energy requirement (RER)''' accounts for both BMR and dietary thermogenegisis. RER is determined by lean body mass, but may vary with age, breed, gender, neuter status, and the presence of disease. For both dogs and cats, RER can be calculated using exponential equations based on body weight using ('''70*BWkg0.75''')<ref>Klieber M. The fire of life. 1961 New York: John Wiley & sons.</ref>. '''A number of factors can influence daily energy requirements, such as breed, reproductive or neuter status, activity level (e.g., sedentary vs. working dog), and environment (e.g., indoor vs. outdoor, kennel/cattery vs. a home)''' and relying on published maintenance energy requirement (MER) equations can be problematic if these variants are not account for.  

'''Resting energy requirement (RER)''' accounts for both BMR and dietary thermogenegisis. RER is determined by lean body mass, but may vary with age, breed, gender, neuter status, and the presence of disease. For both dogs and cats, RER can be calculated using exponential equations based on body weight using ('''70*BWkg0.75''')<ref>Klieber M. The fire of life. 1961 New York: John Wiley & sons.</ref>. A number of '''factors can influence daily energy requirements''', such as breed, reproductive or neuter status, activity level (e.g. sedentary vs. working dog), and environment (e.g. indoor vs. outdoor, kennel/cattery vs. a home) and relying on published maintenance energy requirement (MER) equations can be problematic if these variants are not accounted for.  

'''Normal MER variation in cats<ref name ="Berm">Bermingham EN, et al. Energy Requirement of adult cats. Br J Nutr 2010;103:1083-1093.</ref> can range from 29-85.5 kcal/BWkg0.75''' and in '''dogs<ref name="Bermingham">Bermingham EN, et al. Energy Requirement of adult dogs: A meta-analysis. PLOSone 2014;9:e109681.</ref> can range from 54.5-441.1 kcal/BWkg0.75'''. It is important to note that in both dogs and cats daily MER values can actually fall below calculated RER based solely on body weight. Adipose tissue is less metabolically active than muscle and obese dogs and cats will have lower than expected RER based on body weight measurements alone. Larger cats (>5.5 kg) have lower metabolic energy requirements on a per kg basis than lean or “normal” weight cats<ref name="Berm"/>. In a meta-analysis study on energy requirements of adult cats, the MER was best represented by the equation 77.7 * BWkg 0.711.  

'''Normal MER variation in cats<ref name ="Berm">Bermingham EN, et al. Energy Requirement of adult cats. Br J Nutr 2010;103:1083-1093.</ref> can range from 29-85.5 kcal/BWkg0.75''' and in '''dogs<ref name="Bermingham">Bermingham EN, et al. Energy Requirement of adult dogs: A meta-analysis. PLOSone 2014;9:e109681.</ref> can range from 54.5-441.1 kcal/BWkg0.75'''. It is important to note that in both dogs and cats daily MER values can actually fall below calculated RER based solely on body weight. Adipose tissue is less metabolically active than muscle and obese dogs and cats will have lower than expected RER based on body weight measurements alone. Larger cats (>5.5 kg) have lower metabolic energy requirements on a per kg basis than lean or “normal” weight cats<ref name="Berm"/>. In a meta-analysis study on energy requirements of adult cats, the MER was best represented by the equation 77.7 * BWkg 0.711.