This is what i understand from reading about Coccidiosis and the use of corridThat is my understanding of it. By starving the Protozoa of thiamine you destroy it's ability to absorb nutrients and it starves to death. If you give B1 supplement whilst treating you will negate treatment . However it is advisable to administer a good multi vitamin after treatment, as thiamine deficiency can cause ataxia and all sorts of neurological problems.