DISEASES OF NEWBORN ANIMALS 309 



to the placenta and fetus. This would explain those cases 

 where a given mare bears year after year colts which are born 

 with the disease. In cases of antepartum infection the navel 

 is usually intact. 



Necropsy. — The postmortem lesions vary, depending on 

 whether the case was peracute, acute, or chronic. 



(a) Peracute. There are no marked lesions except those 

 of a general septic infection such as cloudy swelling of the 

 parenchymatous organs, petechias and ecchymoses in the 

 serous and mucous membranes and acute swelling of the 

 lymph glands. 



(6) In acute cases the navel is usually swollen and firm and 

 the navel ring is open. Purulent or putrid exudate may be 

 pressed out. Quite frequently an abscess forms in the ab- 

 dominal wall. The umbilical vein and one or both umbilical 

 'arteries are distended at intervals or throughout their whole 

 length. On palpation they feel firm or fluctuating. When 

 opened & dirty red, often fetid exudate flows out. The inner 

 surface of the bloodvessels may be covered with a fibrinous 

 coagulum and is sometimes ulcerous. The infection may 

 involve the peritoneum, leading to an adhesive peritonitis, 

 causing adhesions among the abdominal organs. The portal 

 vein and its branches show thrombi extending into the 

 liver. 



Metastatic abscesses, especially of the lungs, liver and 

 lymph glands, are not infrequent. Occasionally there may be 

 present pleuritis and pericarditis. A fibrinous or suppurative 

 panophthalmia is not rare. The affected joints, especially 

 the tarsal and carpal, show suppurative arthritis. The peri- 

 articular connective tissue is infiltrated with either a sero- 

 fibrinous or seropurulent exudate; periarticular abscesses are 

 not uncommon. A communication between the abscess and 

 the diseased joint cavity is not unusual. The adjacent tendon 

 sheaths may be also involved. 



(c) Chronic Cases. — The changes here are frequently in the 

 lungs, such as bronchopneumonia, with fibrinous or sero- 

 fibrinous pleuritis, and pericarditis. In the later stages case- 

 ous foci are found in the lungs. The mediastinal and peri- 

 bronchial lymph glands are often enlarged and caseated. The 



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