Wm. M. Rogoff

Studies with phenothiazine and Hypolin for the control of cattle grubs.

The possibility of using phenothiazine as a systemic agent against cattle grubs ( Hypoderma spp.) has been under consideration for many years. Some investigators have noted fewer grub encystments in cattle treated with anthelminthics, including phenothiazine. Early reports were contradictory but interesting. Spence (1952) reported negative results against grubs when using several periodic oral doses of phenothiazine. Worden (1953), however, reported outstanding differences in grub counts of cattle receiving repeated oral doses when compared with their untreated controls. Worden used Hypolin (a proprietary mixture of phenothiazine, di-n-butyl tin dilaurate, and hexachlorethane) as the test chemical. Schwartz et al. (1954) reported reductions in grub numbers in cattle that were allowed freechoice access to phenothiazine in mineral and grain. These conflicting reports and the interest generated by them prompted these studies.