Found this:Kathy - can you point me toward a paper or some reference that resolves the "thiamine uptake inhibitor" part of amprolium with the "okay for ducklings" part? This is not a snarky question, I genuinely have been mulling over this for some time now, and would love to know more.
http://www.ncbi.nlm.nih.gov/pubmed/6878147
Anticoccidial drugs and duckling performance to four weeks of age.
Holderread D, Nakaue HS, Arscott GH.
Abstract
Frequently, publications pertaining to waterfowl state that medicated feeds should not be fed to ducklings and goslings. In some localities, producers and hobbyists who raise a small number of ducklings and goslings can purchase only medicated chick, turkey, or gamebird starter and grower feeds. Because of the lack of documented information on this subject and the numerous requests for advice on this matter, anticoccidial drugs, zoalene, sulfaquinoxaline, and amprolium, were mixed in mash feed and fed to Khaki Campbell male ducklings to 4 weeks of age. No significant differences in mean body weight, mortality, and anatomical development were observed among the treatments. Medicated commercial crumble turkey and chick starter feeds produced significantly better feed conversion than the mash medicated or nonmedicated feeds. These differences can be attributed to greater feed spillage with the mash feed. Some ducklings in all treatments showed unsteadiness of gait and shaky legs. These conditions disappeared when the ducklings were moved from the battery brooder to an outside pen. Zoalene, sulfaquinoxaline, and amprolium used at the recommended levels for chickens and turkeys did not cause any leg or anatomical problems in ducklings.
And I'll look for more.
-Kathy