Feed stores usually have them. Take note of the dosage on the box - it usually states how many pounds the tube will treat. Divide that into a daily dose. Benificial to also take vitamin d and c and some zinc to offset the symptoms of the parasite die off.
Subtle red pill on c02 causing cognitive decline.
https://www.sciencedirect.com/science/article/pii/S001393512200891X