642 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



takes place in a very short time. The average mortality is from 

 fifty to sixty per cent. 



The prognosis is unfavorable in young animals, manifesting 

 weakness, when several organs are involved at once, where lobular 

 pneumonia is pronounced, where diarrhea is excessive, where ex- 

 haustion is pronounced, where the breath is fetid, and finally, where 

 there is a lowering of the temperature below the normal. 



Death is produced by cerebral paralysis, which may end the 

 disease within a few days, or by pulmonary edema, septemia or ex- 

 haustion. The prognosis is more favorable where the animal is 

 older and stronger, where the disease runs a mild course and is 

 localized to circumscribed regions. 



Differential Diagnosis. The distinction of this disease from a 

 simple catarrh is sometimes very difficult to make. In general, 

 however, the multiplicity of the catarrhal lesions aid us in our 

 object, such as simultaneous invasion of the several organs, the 

 young age of the affected animals, the marked elevation of tempera- 

 ture, the general progress of the disease, and especially the pustular 

 eruption. Where the symptoms of cerebral excitement are present 

 the so-called hydrophobia is generally thought of; in fact, in the 

 writer's opinion nearly all, if not all, of the mad-dog scares are in 

 reality canine distemper with the nervous symptoms predominating. 

 It is said that in the latter disease, the aggressive tendency (so char- 

 acteristic of rabies) is absent; but probably the seat of the lesion in 

 the brain has a great deal to do in determining the different symp- 

 toms, as in a case where the nervous symptoms followed very closely 

 upon the general catarrhal symptoms of distemper, these nervous 

 symptoms were decidedly of an aggressive nature. 



When the exanthema is extensive and covers a large surface of 

 the body it may offer a close resemblance to mange ; but in distemper 

 the itching is not so great, and the rapidity with which the exanthe- 

 ma extends, coupled with the other symptoms, as a rule clears up the 

 difficulty. In the early stages it is often very difficult to diagnose 

 distemper from simple catarrhal pneumonia, and at times we are 

 compelled to wait a short while for the other symptoms of distemper 

 to present themselves before we can positively differentiate the two 

 diseases. 



Pathological Anatomy. The air-passages show an inflamma- 

 tory condition, the mucous membrane, which is sometimes pale, is 

 at other times dark red, tumefied and covered with a purulent, thick, 

 brownish-gray exudate mixed with blood-clots; this exudate is even 

 found in the bony cavities of the nasal sinuses. Sometimes the 

 nasal mucous membrane is covered with small ulcers. 



The bronchioles and air-cells of the lungs sometimes only bear 

 evidence of an inflammation of the mucous membrane lining them ; 

 at other times the entire cavities of these small tubes and air-cells are 

 filled with inflammatory exudate. The lungs show these inflamma- 

 tory centers only in spots, while the neighboring air-cells are dis- 

 tended with air. The mucous membrane lining the mouth, 



