DISEASES OF THE HOESEo 541 



lar murmur or the large area of dullness on percussion over the sides 

 of the chest which belongs to simple pneumonia. 



Where there is doubt as to the diagnosis the mallein or the inocula- 

 tion test may be emploj^ed. The mallein test is made by injecting; 

 mallein (a sterilized extract from a culture of glanders bacilli) beneath 

 the skin. If the horse has glanders there results a febrile reaction and 

 a swelling at the point of injection. If the horse does not have glan- 

 ders the mallein has no effect or, at most, it produces a slight swelling 

 only at the point of injection. The inoculation test consists in the inoc- 

 ulation of a susceptible animal (usually a guinea pig) with some of the 

 suspected discharge from the nose or a farcy ulcer. If the material 

 is properly used, and if it contains bacilli of glanders, the experimental 

 animal will develop the disease. Neither of these tests should be put 

 into use excepting by a competent veterinarian. 



The postmortem examination of the lungs shows that the pneumonia 

 of glanders is a lobular, V-shaped pneumonia scattered through the 

 lungs and caused b}^ the specific inflammator}^ process taking place at 

 the divergence of the smaller air tubes of the lungs. In some cases of 

 acute glanders the formation of nodules ma}^ so irritate the mucous 

 membrane of the respiratory tract and cause such a profuse discharge 

 of mucopurulent or purulent matter that the specific character of the 

 original discharge is entirely masked. In this case, too, the submax- 

 illary space ma}" for a few daj's so swell as to resemble the edematous 

 inflamed glands of strangles, equine variola, or larjmgiiis. This con- 

 dition is cspeciall}" apt to be marked in an acute outbreak of glanders 

 in a drove of mules. 



Cases of chronic farcy and glanders, if not destroyed, may live in a 

 depraved condition until the minimal dies from general emaciation and 

 anemia, but in the majoritj^ of cases, from some sudden exposure to 

 cold, it develops an acute pneumonia or other simple inflammator}^ 

 trouble which starts up the latent disease and the animal has acute 

 glanders. 



In the ass, mule, and plethoric horses, acute glanders usually termi- 

 nates b}^ lobular pneumonia. In other cases the general sj^mptoms 

 may subside. The S3miptoms of pneumonia gradually disappear, the 

 temperature lowers, the pulse becomes slower, the ulcers heal, leaving 

 small indurated cicatrices, and the animal m.ay return to apparent 

 health, or ma}" at least be able to do a small amount of work with but 

 'a few symptoms of the disease remaining in a chronic form. During 

 the attack of acute glanders the inflammation of the nasal cavities fre- 

 quently spreads into the sinuses or air cells, which are found in the 

 forehead and in front of the eyes on either side of the face, and cause 

 abscesses of these cavities, which may remain as the only visible 

 symptom of the disease. An animal which has recovered from a case 

 of acute glanders, like the animals which are affected by chronic 



