A rotary float includes an elongated tubular arm with a drive shaft rotatably mounted therethrough. The forward end of the drive shaft is connected to a collet shaft within an extension tube, and transmits rotational force from the drive shaft to the collet shaft. A bit is mounted on the forward end of the collet shaft, for grinding a surface adjacent the forward end of the extension tube. A cap with an opening therein, is frictionally engaged on the extension tube over the bit, to permit floating of an animal's teeth through the opening, while protecting the animal from the remainder of the bit.