_Irregularities of teeth._--There is a fashion of late years, especially in large cities, to have horses' teeth regularly "floated," or "rasped," by "veterinary dentists." In some instances this is very beneficial, while in most cases it is entirely unnecessary. From the character of the feed, the rubbing, or grinding, surface of the horse's teeth should be rough. Still, we must remember that the upper jaw is somewhat wider than the lower, and that, from the fact of the teeth not being perfectly apposed, a sharp ridge is left unworn on the inside of the lower molars and on the outside of the upper, which may excoriate the tongue or cheeks to a considerable extent. This condition may readily be felt by the hand, and these sharp ridges when found should be rasped down by a guarded rasp. In some instances the first or last molar tooth is unnaturally long, owing to the fact that its fellow in the opposite jaw has been lost or does not close perfectly against it. Should it be the last molar that is thus elongated, it will require the aid of the veterinary surgeon, who has the necessary forceps or chisel for cutting it. The front molar may be rasped down, if much patience is taken. In decay of the teeth it is quite common to find the tooth corresponding to the decayed one on the opposite jaw very much elongated, sometimes to such an extent that the mouth can not be perfectly closed. Such teeth must also be shortened by the tooth forceps, chisel, tooth saw, or rasp. In all instances in which horses "quid" their feed, if they are slobbering, or evince pain in mastication, shown by holding the head to one side while chewing, the teeth should be carefully examined. Horses whose teeth have unduly sharp edges are liable to drive badly; they pull to one side, do not bear on the bit, or bear on too hard and "big," toss the head, and start suddenly when a tender spot is touched. If, as is mostly the case, all the symptoms are referable to sharp corners or projections, these must be removed by the rasp. If decayed teeth ere found, or other serious difficulty detected, or if the cause of the annoying symptoms is not discovered, an expert should be called. [Illustration: PLATE IV. AGE OF HORSES AS INDICATED BY TEETH. Longitudinal section of left central lower incisor and cross sections of same tooth showing table surfaces as they appear at the ages of 3, 5, 7, 9, 15, 20 and 25 years. _C_, Cement; _D_, Dentine; _E_, Enamel; _I_, Infundibulum; _K_, Cup; _P_, Pulp Cavity; _S_, Star.]