What is a potential sign of dehydration in livestock?

A potential sign of dehydration in livestock is indicated by the presence of dry mucous membranes. When an animal is dehydrated, the moisture in the tissues decreases, leading to a noticeable reduction in moisture of the mucous membranes, which are typically found in the mouth and nostrils. Healthy animals usually have moist and shiny mucous membranes, so when they appear dry, it is often a clear indication that the animal may need more fluids.

Furthermore, the other options do not effectively indicate dehydration. A shiny coat generally suggests good hydration and overall health. Excessive drinking typically indicates that the animal is compensating for dehydration rather than showing the signs of it. Increased activity, while beneficial in some contexts, does not directly correlate with hydration status and can actually vary based on other factors such as feed, stress levels, or overall health. Thus, the observation of dry mucous membranes stands out as a significant and reliable sign of dehydration.