Years ago we had a problem with our late gsd Cheyenne, the local vet (who misdiagnosed) said it was alergys. After a lot of oinments, this & that, my horses vet looked at him. Covered with "hot spots" ozzing (left stains on the walls) we thought we would have to put him down, it was horrible. Turns out he picked up mange from a fox on the trails. Antibio's cleared it up quickly.
I also have a problem with ticks. We are out on the trails everyday. The only thing I found that helps here on Eastern Long Island is a concentrate I use on my horses "guard star". The "permethrin%" is what you have to look at. Iv'e been checking them & since I started spraying them before we go, they haven't been picking any up.
Carolyn