using Blocks for wildlife is really a bad idea. All diseases can be spread thru Saliva. sharing foods especially salt/mineral blocks is the one thing you want to try to avoid. without going into a lot of detail about CWD, Chronic wasting disease is the one disease you dont want your deer to get CWD is similar to mad cow disease or Bovine Spongiform Encepholopathy (BSE) just ask any farmer how serious BSE is. If states keep allowing blocks to be used in their woods they're only playing roulette with their wildlife. BUT if it's legal in your area and you can use it then by all means use it as you please because if anything happens you're only hurting your own hunting areas because if your area becomes infected with CWD, CWD stems from prions.
Prions are NOT DESTROYED by fire, nor by freezing, nor by disinfectants, nor by operating room sterilization procedures, nor by incineration, nor by intense radiation.
In fact, scientists and government agencies HAVE NOT FOUND ANY WAY TO DESTROY THEM!!
Do you want to risk bringing them into your hunting area???