I have a 2 month old calf that has done very well with growth. However, today I noticed that he appears to have lost weight, back legs appear to be touching as he walks. He appears weak but keeps up well with the herd. His mother is a good milker. The weather is now very hot and I wonder if he has scours. I noticed a small smear on his rear, but it doesn't look like typical scours. I have benamine and nuflor - should I go ahead and give it to him?