COCCIDIOSIS                         49

         It is realised that drugs used for this purpose are limited in their action, and
that results hitherto have been poor and inconclusive. Most of them are supplied
to the affected birds through the drinking water, and when such bodies as mercuric
perchloride, carbolic acid, potassium permanganate, hydrochloric acid, free iodine,
etc., are used, they enter into organic combination with the ingesta and mucous of
the crop and gizzard, and are therefore inert bodies on reaching the intestine and
cæca. Others have no direct action on the parasite but depend on symptomatic
treatment, such agents as astringents, for example. Certain results have been
claimed for the use of dried milk, and similar products which affect a change
of pH in the intestine.

         The oöcyst is impervious, but digestive experiments here show that the ele-
ment forms are easily destroyed by certain chemicals. To achieve this, it is
essential for the agent to be in a free state, at the lower portion of the intes-
tines.

         The possibility of iodine in this connection seemed impressive, and experi-
ments were carried out to find the most convenient form in which it could be
effectively administered. It was decided to use the power of casein to absorb
iodine for this purpose. Casein in milk can absorb large doses of iodine by the
application of heat, and it was found by experiment that this combination did not
affect the hydrolysis of protein and its ultimate absorption as amino acids, and
also that iodine was set free to combine with other organic matter to be passed out
in the excreta.

         This preparation seemed to fulfil the desired conditions and its use was ex-
tended to field work.

         The combination is as follows :—

         To a quart of fresh of separated milk add 3 ounces of the iodine solution, and
heat until it becomes white. This is the stock solution, and 1 pint should be
added to every gallon of drinking water used. The chemical nature of the complex
formed is popularly ascribed to the formation of colloidal iodine.

         Excellent results have been obtained from the use of this treatment on
poultry farms in this province. According to the reports received from 30 out-
breaks recorded, this method of treatment, in conjunction with sanitary measures,
exerts an immediate effect on the death rate and the future condition of the
birds.

                                                                                          D 2