Arthritis. Pyemia 



817 



inflammation, chiefly in the joints. The foal is seen appar- 

 ently well, and two or three hours later is found breathing 

 rapidly, greatly dejected, lying down most of the time and, 

 when caused to rise or helped up, is unable or unwilling to 

 bear weight upon a limb. The lameness may shift to another 

 limb very abruptly or may visibly affect one or more joints 

 in two or more members. The appetite is diminished or de- 

 stroyed. The involved articulations are swollen, hot and 

 painful. The synovial sac is tightly distended with reddish 

 synovia, which may later become purulent. Pyemic ab- 

 scesses may develop in any organ or tissue. 



Pyemic arthritis is commonly associated with alimentary 



Fig. 232 — Abscess ofTJmbilic Vein and Artery. Foal. 

 B, Urinary bladder ; U, umbilic vein passing from umbilicus into perito- 

 neal cavity ; UA, ends of ruptured uterine arteries retracted to fundus of 

 bladder ; VV, umbilic vein. /, Pus cavity in umbilic vein ; 2, abscess in 

 right umbilic artery ; j, thickened walls of left umbilic artery ; 4, normal 

 artery ; 5, thrombus in posterior aorta and iliacs. 



disturbances ranging from severe diarrhea to obstinate con- 

 stipation, and as a part of these disturbances there develops 

 an erratic appetite which causes the foal to swallow hay, 

 straw and other indigestible materials. Unless the course 

 of the disease is interrupted by vigorous medical interfer- 

 ence, it is highly mortal. Almost all severe cases arising 

 within two or three days after birth are fatal. Many are 

 left with disabling joint lesions. 



The lesions vary widely. When the invasion occurs 

 through the umbilicus, especially when aggravated by liga- 

 tion of the umbilic stump, prominent lesions of the umbilic 

 arteries and veins are probable, as shown in Fig. 232. When 

 these vessels become involved, the urachus ordinarily par- 



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