WEED. 495 



Owing to the existing inflammation, a large quantity of fluid escapes from 

 the vessels into the adjoining tissues, and gives rise to the swelling. This 

 fluid has a strong tendency to become consolidated unless it is promptly 

 removed by the lymphatics and smaller veins, whose power of doing so is 

 held in abeyance as. long as they remain inflamed. Hence, the advisability 

 of reducing the inflammation as quickly as possible, and of endeavouring 

 to prevent its recurrence.. 



The fact that two other kinds of lymphangitis (pp. 490 and 492) 

 are caused by specific micro-organisms, suggests the probability of 

 this form of lymphangitis being also infective. 



This disease is generally confined to cart-horses. 



SYMPTOMS. — The inflammation is usually limited to one hind 

 leg, the near one, as a rule ; although, in rare cases, both may 

 become afTected. Or it may appear in a fore leg, usually the off 

 fore. The exceptional cases in which the disease occurs in front, 

 are much milder than when in the hind extremities. There is 

 great lameness. The attack is preceded by a shivering fit or cold 

 stage ; hence, the common designation '' shake." The severity of 

 ■tiie rigor is always proportionate to the duration of the attack. 

 This stage, as in ague, is followed by a hot period, with high fever, 

 frequent, hard and full pulse, and great pain of the affected part. 

 The horse " blows," that is, he breathes as he would do after 

 violent exercise. The glands, at the groin, or at the el how, as 

 may occur in- exceptional cases, swell. The swelling extends down- 

 wards, as far as the foot ; but in farcy it extends upwards. 

 There may be dropsical swellings about the sheath and under the 

 belly. The hot stage is terminated by sweats breaking out over 

 the body. When the swelling subsides, the inflamed lymphatic 

 vessels of the leg appear clearly defined like enlarged veins ; hence, 

 the term " weed," from their supposed resemblance to a vegetable 

 growth. As the complaint, when it occurs, appears generally after 

 a short period of idleness; it has in some places received' the name 

 of '■' Monday morning disease." As a rule, lymphangitis takes from 

 one to two days to become developed ; the severity of the symp- 

 toms remains unchanged for a like period ; and then it slowly and 

 gradually decreases, although the affected limb will, especially after 

 two or three attacks, rarely recover its original size. 



This disease has a marked .tendency to recur. 



After repeated attacks, the limb becomes permanently enlarged 

 — an incurable condition termed " elephantiasis." 



TREATMENT. — At the first appearance of the disease, give as a 

 purgative, a subcutaneous injection of eserine and pilocarpine (p. 

 621), or a full dose of aloes, in ball or drench; and keep the animal 

 on a short supply of food, allowing him only a little laxative diet. 



