may be evacuated.  In singular instances, no synovia is to be aspirated with the needle, and in such cases the amount of iodin injected needs be increased, possibly twenty-five per cent., as experience will indicate.  From two to five cubic centimeters of U.S.P. tincture of iodin is injected through the aspirating needle into the synovial cavity of the joint, and the exterior of the parts are vigorously massaged immediately after injection to stimulate distribution of the iodin throughout the synovial cavity.  Where a bilateral affection exists, two or three weeks’ time should intervene between the treatments of each leg.  A sterile metal syringe equipped with a slip joint for the needle is well adapted to this operation.  Lubrication of the plunger with heavy sterile vaseline or glycerin will prevent the syringe from being ruined by the iodin.

Following the injection, the subject is kept in a stall or in a suitable paddock, so that conditions may be observed for four or five days.  The object sought by the introduction of iodin is not only for a local effect upon the synovial membranes in checking secretions, but the production of an active inflammation and great swelling, which will remain from four weeks to three months subsequent to the injection.  This periarticular swelling should produce and maintain a constant pressure over the entire affected parts for a sufficient length of time until normal tone is re-established.

In some cases, swelling does not develop as the result of a single injection of iodin.  When marked swelling has not taken place within five days, none will occur and a repetition of the injection may be made within ten days after the first treatment has been given.  One may safely increase the amount of iodin at the second injection in such cases by one-fourth to one-third.

In Europe this method of treating bog spavin has been employed by Leblanc, Abadie, Dupont and others according to Cadiot; but Bouley, Rey, Lafosse and Varrier used it with bad results.  Where a perfect technic is executed (and no other is excusable in this operation), no infection will occur if a reasonable amount of iodin is injected.  The dilution of iodin with an equal amount of alcohol has been practised by the author in many cases, but later this was found unnecessary.

Other methods of treatment have been used with success.  Perhaps the most heroic consists in opening the joint capsule with a bistoury or with the actual cautery.  Such practice is too hazardous for general use and is not to be recommended, although good results should follow the employment of such methods if infectious arthritis does not occur.

Line firing over the distended capsule is a practical method of treatment.  This is attended with good results in young animals in many cases, but considerable blemish is caused when sufficient irritation is produced to stimulate resolution.

Vesication also is successfully employed in some instances.  However, only cases of recent origin in young animals—­colts of two years or younger—­yield to blistering, and in some affected colts no doubt recovery would have been spontaneous had no treatment been instituted.