I think that only pertains to amprollium or Corid, not sulfa antibiotic. Amprollium works by mimicing thiamine in coccidia, so any supplementing of thiamine should not be done with amprollium.We’re you using the probiotics while using the sulfa 3? If so make sure that the probiotics did not have vitamins if you were using it for coccidiosis. If the probiotics contain thiamin it will not be as effective in the treatment for coccidiosis.