Page 219 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

194 CHAPTER 1

VetBooks.ir Prognosis and it is a common site for wounds. In approximately
40% of horses the subcutaneous bursa communi-
The prognosis varies, depending on the pathology
and the involvement of bones, joints and supporting
soft tissues, from good (small fragments, especially cates with the more cranial intertendinous calcaneal
bursa and gastrocnemius bursa.
if they can be removed) to hopeless where there is
severe comminution and/or soft-tissue trauma. Clinical presentation
Horses are rarely lame, unless the condition becomes
HYGROMA OF THE TUBER septic or it interferes mechanically with the gait.
CALCIS (CAPPED HOCK) A local fluctuant swelling is present over the point of
the tuber calcis (Fig. 1.374), the size and thickness
Definition/overview of which are dependent on the stage of the condi-
The condition involves a subcutaneous bursa at the tion. Some pain may be evident in acute cases, but in
point of the tuber calcis, which is naturally present chronic cases the swelling is non-painful on palpation.
in a proportion of horses, but is more commonly
acquired. It is defined as a bursitis, as inflammatory Differential diagnosis
processes take place within the bursa. Gastrocnemius tendonitis and associated bursi-
tis; sprain of the long plantar ligament (curb); tar-
Aetiology/pathophysiology sal sheath distension (thoroughpin); luxation of the
Frequently the condition is chronic and character- superficial digital flexor tendon.
ised by the slow development of a bursa as a result
of repetitive trauma to the region, until it becomes Diagnosis
cosmetically unacceptable to the owner. Excessive The clinical presentation of a swelling over the point
fluid is accumulated within the bursa and the wall of the tuber calcis without lameness is very consistent.
becomes thickened. The cavity may become filled Ultrasonography is useful to demonstrate the hygroma
with fibrous bands and subdivided into smaller and its contents, and to differentiate it from other
cavities by septa. Most commonly, it is a non-septic conditions. Radiography is usually not required, but
condition; however, the bursa can become infected where confusion exists as to the anatomical structures
involved, positive contrast radiography can be useful.

1.374 Management
Prevention of further trauma and, therefore, further
inflammation leading to deterioration, by using hock
boots is recommended. Fluid can be drained from the
swelling and corticosteroids can be injected before a
pressure bandage is applied but the results are often
disappointing and short-lived. Surgery should be
avoided due to the very high incidence of wound
breakdown and is only indicated in show horses. It is
important to use a pressure-relieving suture pattern
and keep the horse cross-tied for 14 days. As the pro-
cedure is likely to create a large dead space, the use of
a suction drain for a few days and a pressure bandage
are recommended.

Prognosis
Fig. 1.374 Photograph of a show horse with The prognosis is good for athleticism and guarded
hygroma of the tuber calcis. for cosmesis.