DISEASES OF RESPIRATORY ORGANS 151 



which causes a marked congestion of the mucosa and not infrequent- 

 ly a hemorrhagic inflammation. The lesions extend and involve 

 the sinuses and the ethmoidal cells, and there may be involvement 

 of the optic and olfactory nerves, of the cerebral meninges, and 

 of the brain itself. The usual lesions dn the last-mentioned struc- 

 tures consist of hemorrhages beneath the sheath of the optic and 

 olfactory nerves, congestion of the meninges, and edema of the 

 cerebral tissue proper. Various changes may be observed in other 

 internal organs as a result of high temperature and possibly also 

 of metastasis of the infecting agent. 



Sympioms. — High temperature and inappetence are usually the 

 first symptoms of the disease. Sneezing, and vigorous rooting or 

 rubbing the nose, are followed by epistaxis, edema of the snout, and 

 difficult breathing. The affected animals may be blind in one or 

 both eyes, and if there is meningeal involvement the pigs will evi- 

 dence extreme excitement and finally die in a comatose state. The 

 disease may result fatally in a very short time, its course in the 

 most fatal epizootics being from three to six days. A chronic or less 

 fatal form has been observed in which the course of the disease 

 varies from one week to several weeks, and some of the animals 

 may recover. 



Treatment. — In the acute form of infectious nasal catarrh treat- 

 ment has not been successful. From the experience of those veterin- 

 arians where this disease prevails it seems best to recommend de- 

 struction of all affected animals. An antitoxin may be prepared 

 and used to offset the injurious influences of the toxic substances 

 produced and eliminated by the Bacillus pyocyaneus. Prophylac- 

 tic sanitary measures should be instituted and rigidly enforced on 

 premises where this disease abounds. 



TUMORS 



Various tumors have been observed in the nasal cavity of swine 

 or involving some related structure. Almost all of these tumors have 

 been of the benign type and therefore interfere only mechanically. 

 Pedunculated fibromas are not so common in swine as in some other 

 animals. 



Larynx 



CATARRHAL LARYNGITIS 



Inflammatory disturbances of the larynx are relatively common in 

 swine but are not of sufficient gravity to warrant a lengthy discussion. 



