After very heavy rains and most recently after a hard freeze, I have cows that appear fine one day and are down the next never to get up. The whites of the eyes appear very swollen and the vet has taken tissue & blood samples to no avail. I have two different fields of commercial animals and am feeding the same hay and feed supplements at both. Only one field has this problem. Help! Have lost 3 cows and their 3 calves in the last 2 weeks and have 2 more cows down today!