What happens to Boxer in Chapter 9? Why does he not mins his situation?

In Chapter Nine, Boxer is still suffering from an injury he incurred in battle, but he works as hard as ever. Unfortunately, Boxer's hard work, as well as his injury lead him to collapse while helping to build the schoolhouse. Boxer is out of commission for two days, when Napoleon makes the decision to send him to a veterinary hospital. Sadly, Boxer isn't going to the hospital, but rather the glue factory. Napoleon, of course, made a profit.