I plan to increase my flock size in the next 2 months. The chickens I have are 6 buff Orpingtons and have displayed these signs progressively since I got them from the 4H girl last summer. The first sign of trouble was the roosters comb turning purple at times.I mistakenly thought was a diet issue. Now with the long cold winter they are displaying swollen faces, sneezing, and some raspyness.( I brought them in and put them in the basement in december due to the cold.Still there cuz their sick.)The other day they were twisting their necks in a weird way so I gave em vitamins and they are acting normal again & happy but still swollen and raspy.Can I use Vet RX or will I have to cull them before the new chicks show up?