PRINCIPLES OF VETERINARY SURGERY 329 



Thromboses obstruct the frozen vessels, then the skin and 

 subjacent tisues, being deprived of nourishment, become 

 necrotic. Utchinsky's experimental studies of lesions in the 

 tissues caused by cold, show that ether, in only four minutes, 

 caused contraction of the blood vessels and heaping up of 

 the red blood corpuscles, and after twelve hours accumula- 

 tion of leucocytes with the formation of intra-epidermic 

 vacuoles, while a more intense refrigeration provokes 

 heemorrhages in the papillae. 



That frozen organs can be restored to their normal con- 

 dition has been shown experimentally by Hunter, who froze 

 the ear of a rabbit until an incision with a bistoury brought 

 no blood, and then warming the organ to its original tem- 

 perature, found that the circulation had resumed. Frozen 

 organs regain the normal temperature by degrees, and then 

 become the seat of a rather acute inflammation, which grad- 

 ually subsides. 



TREATMENT. — When animals have been exposed to 

 intense cold they should not be immediately placed in a hot 

 stable. Dogs should be kept away from stoves. If this rule 

 is ignored, simple accidents may terminate in gangrene. 

 Gentle rubbing with snow or ice is very efficacious against 

 frost-bites. When ulcers or scabs have formed the lesion 

 should be treated with respect to antisepsis. They should 

 be thoroughly cleansed and coated with a protecting sub- 

 stance. Iodized glycerine or an iodoform ointment i^ very 

 suitable for frost-bites in the extremities, and a clean, dry 

 litter is indispensable. In dogs Moller successfully made 

 use of warm baths from i6 to i8 degrees C, of which the 

 temperature was gradually raised. Occasionally amputa- 

 tion of a frozen extremity may become necessary in the dog 

 or cat. 



Systemic disturbances resulting from exposure to cold 



