THE FORMATION OF SADDLE-GALLS. 491 



areas of skin are compressed, leading to vascular distension and 

 rupture ; but while pressure continues little extravasation occurs. 

 So soon, however, as the saddle is taken off, blood and lymph pass 

 from the ruptured vessels into the perivascular spaces. As in other 

 bruises, if the skin were not pigmented, reddening might be noticed. 

 At first a serous fluid accumulates in the interstices of the cutaneous 

 tissue, and at a later stage, more and more white corpuscles appear, 

 with plastic infiltration. The gall consists of a circumscribed firm 

 swelling, caused by extravasation into and infiltration of the cutis. 

 It may be soft, occasionally fluctuating, and without sharp borders, 

 as when blood and lymph are freely poured into the loose subcutis. 

 Should this condition develop under the fascia, the swelling is less 

 sharply defined and more tense. 



The lesion, when situated on the withers or spine and caused, 

 as indicated, by bruising of the skin covering the superior processes 

 of the vertebra? is less sharply defined, more dispersed, and often 

 shows fluctuation. Although it may not be painful at first, it becomes 

 so if the vertebrae are injured. While lesions of the withers and 

 spine are generally subcutaneous, those of the saddle-bed are generally 

 cutaneous. From pressure and friction of the girths and other parts 

 of the harness, hair and epidermis are often rubbed off. If bruising 

 also occurs, cutaneous swelling ensues. The condition is one of 

 cutaneous or subcutaneous bruising, which sometimes consists in 

 rupture of the tissues and smaller vessels, less frequently in injury 

 of larger vessels and consequent extravasation. 



Symptoms. Saddle-galls are best discovered half an hour to 

 one hour after unsaddling ; it usually takes this time for their ap- 

 pearance. They generally vary in size from a sixpence to a five- 

 shilling piece ; are tense, hard, somewhat painful, warm, and sharply 

 marginated. The larger are always flat. Should the hair over 

 the saddle-bed be wet, these points of pressure dry first, producing 

 isolated dry spots. Not infrequently they are itchy, and the animal 

 bites or rubs them. Bruises of the subcutis are diffuse, sometimes 

 cedematous, sometimes fluctuating, and are usually more painful, 

 especially on pressure. Saddle-galls are best detected by passing 

 the hand over the withers, spine, and the saddle-bed, when 

 thickening, firmness, or tenderness may be discovered. When the 

 tender spot is touched or pressed the animals bend the back or move 

 away. This is specially noteworthy in the region of the withers, 

 for the detection of such swellings in this site is otherwise somewhat 

 difficult, 



Disease implicating the ligamentum nucha? is characterised by 



