506 GENEEAL DISEASES. 



hard or had abscesses, although occasioinally they might become 

 somewhat enlarged. 



Fig. 146 shows the near hind leg of a horse in South Africa 

 which was suffering from this disease. The inside of the leg was 

 ulcerated in a manner similar to the outside of the limb. 



Post-mortem examination often shows that suppuration has ex- 

 tended to the kidneys, but never to the liver, spleen or lungs. 



TRANSMISSION OF THE DISEASE.— Ulcerative lymphangitis 

 is probably communicated by contagion only from one animal to 

 another. Nocard considers that it is not very readily transmitted, 

 and that consequently it is not a particularly dangerous disease. 



TREATMENT. — Antiseptic treatment applied to the ulcers or to 

 the interior of the abscesses after they have been opened, is often 

 followed by rapid healing, which produces only a temporary good 

 result, for the disease may re-appear at any time in other places. 



Weed {Lymphangitis) 



is a condition of the system characterised by inflammation of the 

 lymphatic glands of one, or more, of the limbs. 



The usual CAUSES are over-feeding on nutritious food ; a 

 change of food — especially one of "green meat" — given in a 

 large quantity; and neglect of regular exercise. Errors of food 

 and want of exercise are, generally, combined in the production 

 of this disease. Wounds of the feet sometimes give rise to a 

 form of this complaint. 



NATURE OF THE DISEASE.— Besides the arteries, capillaries and veins, 

 which are essentially concerned in the conveyance of blood, there is another 

 system of vessels called the lymphatics, the function of which is to take up 

 nutritive material from the intestinal canal, and, also, to remove waste 

 products from the tissues. The lymphatics somewhat resemble the veins ; 

 as they are, at first, very minute, and, then, gradually enlarge. In health, 

 the superficial lymphatic vessels are not outwardly apparent to the eye ; but, 

 when irritated, they become swollen and painful. In the hind leg, which is 

 the usual seat of this disease, they follow the course of the great saphena vein 

 which runs up the inside of the hock and thigh. Exercise quickens the circu- 

 lation of the fluid (lymph) which flows through the lymphatics ; but want 

 of work naturally tends to retard it. When lymph stagnates — if I may 

 use the term — in the lymphatics, especially, if the horse, for some time 

 previously, has been fed on highly nutritious food, it is apt to cause irritation in 

 the glands through which is passes. It is not improbable that, owing to its 

 retention in these vessels, the lymph undergoes some unhealthy change. 

 When an animal has been fed on highly nitrogenous food, the waste products 

 of the tissues will be much more unstable in their composition than they would 

 be were the percentage of nitrogen less. Again, we are aware that the circu- 

 lation of both blood and lymph in the limbs of the horse — especially in the hind 



