Some swelling is desirable and much swelling sometimes results and persists for weeks.  This is not in any way likely to cause permanent trouble; and if the technic of injection is skilfully executed no infection will follow.

By persistent and careful use of suitable elastic bandages, the support thus given the parts, together with the absorption of products of inflammation which constant pressure occasions, some chronic cases of synovial distension of tendon sheaths recover in two or three months and this without other treatment.  Such good results are not to be expected in aged subjects, nor in horses having at the same time, chronic lymphangitis.

Where bandages of pure rubber are employed great care is necessary, if one is not experienced in their use, lest necrosis result.  Where bandages are uncomfortably tight the subject will manifest discomfort, and an attendant should observe the animal at intervals for a few hours (where there may be some doubt as to the degree of pressure which is exerted by elastic bandages) and readjustment made before any harm is done.

Arthritis of the Fetlock Joint.

Anatomy.—­The anatomy of the metacarpophalangeal articulation is briefly reviewed on page 58 under the heading of “Anatomo-Physiological Review of Parts of the Foreleg.”

Etiology and Occurrence.—­The chief causes of non-infective arthritis of the fetlock joint are irritations from concussion and contusions due to interfering.  The condition occurs in young animals that are over-driven in livery service or other similar exhausting work, where they become so weary that serious injury is done these parts by striking the pasterns with the feet—­interfering.  In these “leg-weary” animals, that are always kept shod with fairly heavy shoes, much direct injury is done at times by concussion due to self-inflicted blows.  In older animals, where there exists similar conditions, with respect to their being worn from fatigue and, in addition, periarticular inflammatory organizations, arthritis is not of uncommon occurrence.

[Illustration:  Fig. 30—­Rarefying osteitis wherein articular cartilage was destroyed in a case of arthritis of fetlock joint.]

Symptomatology.—­In true arthritis there exists a very painful affection which is characterized by manifestations of distress.  The subject may keep the extremity moving about—­where pain is great—­suspended and swinging.  There is swelling which is more or less hot to the touch and compression of the parts with the fingers increases pain.  Lameness is always pronounced and no weight is supported with the affected member in very acute and generalized arthritic inflammations.  There occurs the usual facial manifestations of pain—­the tense condition of the facial muscles and the fixed eye and nostril are in evidence.

In cases where there exists a synovitis or where a very limited portion of the articulation is involved, a somewhat different clinical picture is presented.  Then, the disturbance causes less distress; local swelling and evidence of supersensitiveness are not so pronounced and lameness is not intense, though weight-bearing is painful.