Effects of spaying on activity levels, food intake, and body composition of cats

The objective of this study was to examine the effects of spaying on activity level, food intake and body composition of cats. Eight adult (> 1 yr old) domestic shorthair cats were fed a commercial dry diet throughout the study. At the end of a two wk baseline period (wk 0), cats were spayed and fed to maintain an ideal BW for 12 wk. Food intake was measured daily and adjusted 2 times per wk to maintain BW. After 12 wk, cats were then fed ad libitum for an additional 12 wk. Dual energy x‐ray absorptiometry (DEXA) was used to measure body composition at wk 0, 12, and 24. Activity levels were measured for 9 consecutive days prior to wk 0, 12 and 24 using Actical collars (Mini Mitter, Bend, OR). Data were analyzed using the mixed model method of SAS. To maintain ideal BW during the first 12 wk after spaying, food intake had to be significantly decreased (P<0.05; 30.6% decrease from baseline). Body fat percent did not change between wk 0 and wk 12. Total activity level decreased (P<0.05) from wk 0 to 12. Although activity level during light hours did not change, activity during the dark period drastically decreased (P<0.001) after spaying (75% decrease). Our results suggest that spaying increases the likelihood of obesity by decreasing physical activity levels, particularly during the dark period. Thus, in order to maintain an ideal BW after spaying, body condition score and food intake need to be closely monitored and adjusted accordingly.