322 PRINCIPLES OF VETERINARY SURGERY 



Erythema, (2) Simple inflammation, (3) Inflammation with 

 secretion or suppuration, and (4) Necrosis of the tissues. 



Local Symptoms. — The physiognomy of the lesion varies 

 markedly with the nature of the body that has cauterized 

 it. Burns with boiling water may be diffused, but are always 

 superficial, and those with solid bodies are deep but lim- 

 ited. Burns from sulphuric acid are generally diffused and 

 reddish and are covered with a reddish-brown scab. 



Circumscribed bums manifest themselves, when produced 

 by a solid body, by disappearance of the hairs, which are red- 

 dened at the point touched. The skin becomes dark red and 

 erythematous, and the pain is brief but acute. If the action 

 of the heat has been intense, the skin becomes tumefied and 

 blistered, or else shrivels up and sloughs away. When the 

 surface is extensive there is erythema around the periphery, 

 blisters in the middle zone and necrosis in the center. The 

 skin may be destroyed and the subjacent tissue partly car- 

 bonized. Slight burns produce no systemic disturbances. 



Diffused burns, although superficial, will give rise to seri- 

 ous general phenomena, which are- still more accentuated if 

 the burn is deep. They may affect the muscles, the blood- 

 vessels, the nerves and even the bones. In these cases the 

 periphery of the burned area exhibits every degree of burns 

 and the central zone contains a scab which emits the odor of 

 scorched flesh. Cicatrization is only possible when the dam- 

 age is limited. Slight burns last but a short time, although 

 those exhibiting a scab may recjuire a considerable time to 

 heal. 



General Symptoms, — Diffused burns are followed by gen^ 

 eral complications. Animals suffer from nervous shock and 

 pass into a comatose state as the result of the intense irri- 

 tation of the sensitive nerves. The pulse is feeble, the respi- 

 ration irregular, the temperature lowered and haemoglob- 

 inuria appears. Horses eject an intensely dark red urine, 



