Field control of bovine parasitic otitis.

Nicotine used at approximately 2 ppm in 0.25% toxaphene dip wash was found to be 95% effective in the treatment and control of bovine parasitic otitis after dipping clinically affected cattle twice weekly for twelve weeks. Only three of 64 clinically affected animals failed to recover completely following the above treatment regime. The viable nematodes, Rhabditis bovis, which were easily isolated from dip tanks prior to treatment, could no longer be isolated 48 hours following dip tank treatment with nicotine. The above results are very significant since the control of bovine parasitic otitis would greatly enhance the productivity of cattle.