That would be the pool grade form. You want food grade. People sometimes mix it into feed to treat for worms. I have used it on my cats and in my house to treat for fleas a few times, and it was very effective. It is fairly cheap to buy on Amazon in bulk containers. A little goes a long way.
Google search on Diatomaceous Earth for fleas and ticks...there is info that comes up. It might be a good thing to try.
I would try the DE first and if that doesn’t work try some ivermectin pour on. Ticks are not listed as something it covers but one of our fields we have for our cattle is terrible about ticks and it takes care of it for them. Pour on is also safe for goats. That is my wormer of choice for my goats........I know there is a big debate on if it actually works well as a wormer and I’m not opening that up, I am simply stating that I give to my goats (as a pour on NOT orally) with no ill effect
I have used the pour on as it is meant to be applied by striping the goats top line with a needless syringe when needed. It is very effective for deer worm problems. It has helped goats here that were already showing symptoms and walking all messed up with the hyper extension of the legs. It has cleared up mites and probably ticks as well. What I use to prevent ticks is Gordon's Spray from TSC. Every few days before walking the goats out I mist them in the summer. Ticks like to climb on animals when it is wet out and they also like to drop on them from trees. Especially Willow trees around dusk. I have also dusted with DE but mostly use it under fresh bedding in the stalls to prevent insects and mites. So it is also a good thing to have on hand. If you are going to dust an animal it is good to cover their eyes and make sure you are not in the wind where it will blow back on you or up their noses and in their eyes.