Earth's changing seasons affect weather patterns around the world which directly impact ambient temperature. These temperatures and the amount of seasonal daylight cause the migratory, feeding and breeding patterns of Earth’s creatures. The sun has a direct impact on water evaporation, rain, wind, grass lands, agriculture and oceanic life like algae, and fish. All life follows the cycle of the seasons, including us and our pets.
Recently, studies conducted over decades by research scientists from numerous universities were collected and summarized by The National Research Council in an updated 2006 publication. In this summary, over 40 scientific research papers imply and often conclude the effect of ambient, thermal and seasonal temperatures on companion animals has a profound impact. Specifically, in the publication "NRC Nutrient Requirements of Dogs and Cats," Chapter 11 - Activity and Environment, valid scientific evidence is published that discusses the effect of ambient temperature on a pet’s metabolic energy requirements (MER), which may increase as much as 40% when temperatures fall. Conversely, as ambient temperatures rise, less metabolic energy (MER) may be required. The NRC book is available by contacting www.NRC.org.