CATARRHAL IXFLAMMATIOX OF THE LUXGS 141 



ranging in size from that of a small pen to a coffee Ijean (Tracheitis veru), 

 Cosa verminosa (Rabe) . These parasites cause severe coughing, dyspnoea 

 great weakness, fever, vomiting, and colicky pains. 



Strongylus Vasorum (Baillet). — These are long thread-like worms 

 which lodge in the right side of the heart and the pulmonary artery. The 

 eggs are carried by the blood into the lungs, and lie in the minute branches 

 of the bronchi (bronchioles) forming fine nodules resembling those of 

 tuberculosis; the embryo is liberated, gets into the bronchi, causing irrita- 

 tion and coughing, and the young parasite is expelled with the mucus 

 coughed up, or some of the parasites find their way into the alimen- 

 tary tract, then into the veins, and are carried back to the heart. 

 Animals afTectcd present the following symptoms: dyspncea, ascites, and 

 emaciation. 



The Spiroptera sanguinolenta (see page 51) also find their way into 

 the air-passages, causing chronic bronchitis. 



DISEASES OF THE LUNGS. 



Catarrhal Inflammation of the Lungs; Pneumonia. 



{Catarrhal Pntumonia; Lobular Pneumonia; Broncho-pneumonia.) 



Etiology. — Catarrhal inflammation of the lungs generally originates as 

 a secondar}^ disease following Ijronchitis, by an extension of the inflamma- 

 tion of the small bronchia into the alveoli, or from the obstruction of the 

 bronchial tubes; it may originate primaril}' as pneumonia or in the pul- 

 monary form of distemper. Certain animals, such as very old dogs, or 

 young animals, undeveloped and underfed, as well as animals that have 

 gone through some acute illness, are predisposed to the development of 

 lobular pneumonia. Lobular pneumonia is caused by accumulations of 

 mucus in the trachea which may be only imperfectly coughed up, or in 

 very weak cases, lying in the tubes, become decomposed and putrid, and 

 so act as an irritant. These particles of mucus are carried into the deep 

 portions of the lungs, directly on the aveoli, and form a capillary bronchi- 

 tis; it may become converted into a catarrhal pneumonia. In some cases 

 particles of food, medicines, especially thick mixtures, get into the lar- 

 ynx when the animal is unconscious or where there is partial paralysis of 

 the throat. These substances penetrate into the lungs and are very 

 difficult to dislodge from the bronchia. This form of the disease is gener- 

 ally termed traumatic or aspiration pneumonia. 



Roberts has described catarrhal pneumonia in an epidemic form at- 

 tacking all ages, developing a high temperature, and loss of 30 per cent. 

 8avaresc has described a specific pneumococcus, but in all probability 

 both observers have described a condition similar in nature. 



