182 C. M. McCay 



Among the larger species of domestic animals, the dog, 

 the sheep and the monkey all have merit. Thousands of very 

 old dogs are killed each year in kennels because they have 

 become too old for breeding purposes. Part of these are 

 available for research laboratories, especially in fields such as 

 nutrition where the animals may not be mutilated. For some 

 years, we have had a supply of such dogs given us. We have 

 accepted any registered, purebred dog that exceeded eight 

 years of age. In some cases, such as dogs from kennels, no 

 conditions are attached to the gifts. In the case of pets, we 

 have abided by any restrictions placed by the giver except 

 we have reserved the right to put the dog to sleep in case it 

 was suffering from an incurable disease. 



Although the dog is one of the most difficult species to 

 study in nutrition because of such factors as emotional 

 attachments and reactions to environment, it may prove the 

 most useful for old age studies because it is large enough to 

 obtain blood samples and because of the extensive knowledge 

 built up during several centuries in regard to the physiology 

 of the dog. 



Sheep have been little used in the study of ageing but are 

 available in large numbers at modest prices. Old ewes when 

 they are sent to the slaughter house to be rejuvenated into 

 lamb for the consumer are worth very little and afford 

 inexpensive research material. 



Some discussion has been given to the use of monkeys for 

 old age research. This use was debated in Washington during 

 several years when the colony of monkeys on the island off 

 Puerto Rico was being abandoned by the universities that 

 established it. No progress was made in regard to this use of 

 the colony. One American university has toyed with the idea 

 of establishing a monkey colony within their physiology 

 division for old age research. This would be very expensive 

 and would require a plan of operation under a group of 

 scientists that would be continuous since the monkeys might 

 outlive their masters. 



The most neglected of opportunities are found among men 



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