I have horses on two totally separate pastures and its been a couple weeks since they finished their lick tubs and now I am starting to see warts appear on their muzzles. I know it is a virus and is contagious but I did not see any visible signs of ANY of them having them before I gave them these lick tubs. All of the tubs were the same brand from the same store. The filly that has it the worst is coming 3 and the other girls are 8+ yrs old. Then my gelding who is on a totally separate pasture about 15 miles away has a couple and he is coming 4. I am not sure if they can get them from other horses even if there are no visible signs of them or if maybe someone has heard of horses getting warts from something in a lick tub. I read up that they will go away on their own and all but if it is caused from a lick tub then I need to let the company know what is going on. Thanks for any info!