Q: I use rubber mats over a concrete floor in my box stalls. I use only enough sawdust to absorb the urine and moisture in the stall and clean it out completely each day. I have never seen a horse lay down in the stall. Is there any reason to add more bedding in the stalls?
A: Horses need to lie down in order to get an adequate amount of deep sleep and will eventually, over weeks or months, become sleep deprived if they cannot or will not lie down for some reason. Opinions vary, but research on the subject suggests that relatively hard ground doesn't usually deter horses from lying down and getting enough sleep. Wet ground and deep mud will be a significant deterrent, however, as will a slippery surface.
If it were only one of your horses that never seemed to lie down, I would worry about musculoskeletal or lameness pain playing a role. Older or arthritic horses, for example, tend not to lie down as much as they should and go on to suffer sleep deprivation. In those cases, treatment of the pain is very helpful. If none of your horses lie down while in the barn, it makes me wonder whether they prefer to lay down outdoors for some reason. If you are worried, it is certainly worth running an experiment by bedding them more deeply for a time and looking for any change in their sleeping behavior.
By Christie Ward, DVM, University of Minnesota