Recently I have been having a problem with some of my older breeder mice. I have noticed one male, and two females, from my four 1.2 breeding groups, have tumors. The two females are completely unrelated, and not in the same group
Male:

Females:



Also, all the females in three of my groups have these sores on their bellies. All are nursing, but I don't think that is what it is from. My younger trio doesn't have this problem.


These issues all showed up just in the last month. The only change that has been made is i switched all my feeders over to Purina's Nature's Match hog feed. I don't know if I should attribute the problem to this though, as the young trio was raised on it and is showing no issues, none of the babies ranging from pinks to hoppers show any changes, and my rats and ASF's are showing no changes. I was hoping to get other's opinions on what this could be, if i need to switch foods, and if all the mice need culled or just those showing issues. Or, if the mice without tumors bellies may heal. Thank you for any input.
Draven