Hi Freedom86
Two dozen visible ticks sounds quite a lot to me. I think your best course of action would be to take advice from the nearest hog carer/rehbilitator (you can get contact details of the nearest ones by ringing 01584 890801). I wouldn’t try to remove them yourself – could do more harm than good – also a hog with a heavy tick load may have some underlying health problems.
I don’t know anything about DE spray, but it’s best not to use chemicals with hogs around – you could check that out with the hog carer/rehabilitator, too.
Good luck.
