460 CHRONIC INFECTIOUS DISEASES 



pea to a walnut. They soon break down forming ulcers. 

 They may appear without infiltration of the adjacent con- 

 nective tissue, but very commonly a zone of reactive inflam- 

 mation surrounds them. The ulcers are irregular in shape 

 with ragged edges which overhang the base. The base of 

 the ulcer is usually of a dirty, gray color, although it may be 

 covered by a brownish scab. The discharge may be scant 

 and thin or more copious and thick. In the former case it 

 has an oily appearance and a very viscid consistency. In the 

 latter, a thick pus is discharged which does not adhere readily 

 to the hair. While the ulcers are generally indolent, they not 

 infrequently heal leaving behind small scars which do not 

 entirely become covered with hair. 



The lymph vessels in the neighborhood of the nodes and 

 ulcers are frequently swollen, appeariag like cords or ridges 

 under the skin. They are usually hot and sensitive. After 

 remaining for a time they may gradually disappear, or along 

 their course ulcers erupt. The superficial lymph glands 

 (inguinal, popliteal, prepectoral) may become swollen, hot 

 and tender. Later they are hard and less sensitive. 



In chronic skin glanders there is a tendency for the skin 

 and subcutis of one or more limbs (especially the hind ones) 

 to undergo fibrous thickening (elephantiasis), which ends 

 abruptly at the hoof. Quite often the patient is lame. 



Pulmonary Glanders. — Nearly every case of glanders begins 

 in the lungs. As a rule, however, the earlier symptoms of 

 pulmonary glanders are so vague that a diagnosis from 

 physical examination alone is impossible (so-called "occult" 

 glanders). As in tuberculosis of the ox, months may elapse 

 before the infected patient shows clinical evidence of the 

 disease. In the meantime a number of horses may become 

 infected by the unsuspected "occult case." The patient 

 may show occasional cough, which is usually dull, weak, 

 and dry. Less often periodical, slight, nasal hemorrhages 

 (epistaxis) are noted. The horse may tire easily at work and 

 show dyspneic symptoms resembling "heaves." From time 

 to time the temperature may be elevated 1° or 2°. Percus- 

 sion of the thorax usually gives negative results. In rare cases 

 dulness over an area of the lung may be determined, which 



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