592 DISEASES OF THE AETERIES AND LYMPHATICS. 



instances, blood in a liighly fibrinous condition owing to meta- 

 morphosis of tissues. The first is produced by over-feeding, 

 more particularly when the animal is not called upon to per- 

 form his ordinary labour ; and the irritation commences in the 

 mesenteric glands, for it has been shown that every meal which 

 is eaten produces a certain irritation in these glands ; tlie con- 

 stituents of the chyle conveyed to them acting as physiological 

 stimuli to the gland substance, whereby they become enlarged. 

 This irritation extends from the mesentery, along the chain of 

 lymphatic ganglia imbedded in the sub-lumbar and deep inguinal 

 regions which connect the thoracic duct with the first visible 

 lymphatic glands — the superior inguinal ganglion. The course 

 of the disease supports this view of its pathology ; its peculiarity 

 being the way in which it extends from above downwards ; the 

 extension downwards along the limb affected being merely a 

 continuation of the process which has abeady taken place in 

 the glands within the cavity of the abdomen. In some instances 

 lymphangitis is preceded by symptoms of intestinal irritation, 

 colicky pains, and constipation of the bowels. This latter con- 

 dition is generally constant, unless in those instances, common 

 in Scotland, where the disease is produced by over-feeding on 

 green food, particularly upon rye-grass, when, instead of consti- 

 pation, a condition approaching to diarrhoea is often witnessed. 



When the lymphatics are inflamed in consequence of the 

 blood being in a highly fibrinous condition, brought about by 

 metamorphosis of tissue, it will be found that the animal has 

 not been eating for some days: in one instance -within my 

 recollection, sixteen days elapsed before any manifestation of 

 lymphangitis. An explanation is difficult, and can only be 

 arrived at by assuming that the vitality of the animal was 

 supported by the pabulum derived from its own tissues ; and 

 that such nutrient material, being highly loaded with fibrine, 

 was calculated to act as an irritant to the glands and ducts of 

 the lymphatic system. 



Treatment. — In the first stage — that of rigor — fomentations 

 to the affected extremity, warm clothing, purgatives, and at the 

 same time allowing the animal to drink a moderate quantity of 

 water. The administration of stimulants, unless the rigor be 

 very continuous, is not called for ; indeed, stimulants are apt to 

 be productive of harm, by causing a powerful reaction ; but 



