I'm new to this forum and was just reading through some topics. I use the Safeguard blocks on my cows with good success. My cows are accustomed to licking blocks or tubs. Sometimes it does take about a week for them to clean them up. One trick I discovered is when you buy the blocks, take the covers off and inspect them. Some of them that have been sitting awhile will get stale on the top. Take you knife and check the freshness. Also, the worms that safeguard products target are different than the ones that ivomec or Noromectin target. The only injectable that covers same as safeguard is the Long Range injectable. So you should use both types to cover all your worms. Also, i have some rougher country that I run cows and a lot of it is wet. I have ALOT of flukes. Ivermectin or Noromectin PLUS are the only injectables that kill ADULT flukes. Otherwise Valbazen as a drench. I guess there are 2 different types of flukes and some experts say these products only kill one kind, but I have found that the experts can't agree on this. I just give and and hope for the best.