A practical approach to weight loss in adult horses

Weight loss means that an animal has been losing weight or body condition score over a period. Weight loss is more noticeable when acute, but it may be more difficult to identify initially if the loss of body condition score or weight is progressive and sustained in time.

In general, for domestic populations of leisure horses with daily access to pastures, a body condition score (BCS) of 5/9 on the simplified 9-point system for body condition scoring horses (Kohnke, 1992; Renelle et al, 2018) is considered ideal. The use of the horse should be considered to determine the ideal BCS (Mair, 2002). Seasons have an important effect on BCS and weight. For a leisure horse with daily access to pastures in the UK, a BCS of approximately 6/9 is expected in summer and around 4/9 in late winter (Giles et al, 2014). It should be considered that, depending on the husbandry and working conditions, seasonal variations may differ. For instance, in a study on thoroughbred horses kept on a diet with a constant energy intake throughout the year, the BCS of males peaked in autumn and winter and reached a nadir in spring, whereas the BCS of mares peaked in autumn (Takahashi and Takahashi, 2017). Furthermore, breed, use, sex, physiological status (for example, pregnancy or lactation status) and extreme weather events have an impact in the seasonal variation of BCS and weight (Brinkmann et al, 2012).