264 SWINE PRACTICE 



The best method to pursue in cases of viciousness in swine is to pre- 

 pare them for slaughter and market them as soon as possible. 



SUNSTROKE AND HEAT STROKE 



It may be possible to differentiate between the sunstroke and heat 

 stroke in man, and possibly also in horses, but such a distinction is 

 scarcely warranted in swine. 



Etiology. — Sunstroke if it occurs in swine is caused by the rays 

 of sunlight acting upon the nerve-cells of the brain. Heat stroke, 

 overheat, heat exhaustion or hyperthermia are the result of ther- 

 molysis. Swine, especially when in condition for slaughter, are pre- 

 disposed to overheat because of the excessive accumulations of fat. 



Driving swine in droves is occasionally accompanied Tiy cases of 

 heat stroke, and this may also be observed in carload lots in which 

 the swine are crowded and the shipment made in extremely hot 

 weather. The same condition arises in swine that are hauled in 

 wagons, if proper precautions are not taken. Lack of proper shade 

 predisposes the swine to sunstroke and to heat stroke. 



Lesions. — The gross lesions that characterize overheat are prac- 

 tically the same as asphyxia and consist of parenchymatous degen- 

 eration of all essential structures as liver, kidney, heart and volun- 

 tary muscle. The blood is usually dark, and does not coagulate 

 readily and the veins are engorged. The lungs are usually engorged 

 with venous blood. There may be ecchymotic cardiac hemorrhages. 

 Microscopically, the nerve cells are found to contain- coagula, and 

 there may be cloudy swelling of all parenchymatous tissues. 



Symptoms. — Uncertain gait, dullness, depression, increased respira- 

 tion, and anxious expression are the principal syniptoms observed in 

 the early stages of these conditions. The temperature may be very 

 high. Muscular tremors, falling to the ground, and convulsions are 

 the final symptoms. The course of the disease is short. In some 

 instances the animal succumbs within a few minutes after the onset; 

 in other cases the animal may live for from one to three days, and 

 in rare instances may recover. 



Treatment. — Place the animal in a shady spot, give rapidly diffus- 

 able stimulants, and apply cool but not cold water over the body, 

 and if possible, use ice packs on the head. 



LIGHTNING STROKE 



Lighting stroke sometimes occurs in swine, particularly among 

 those in pasture. The lesions of lightning stroke are not well marked. 



