Chapter_19 



EFFECTS OF LARGE DOSES OF NEUTRONS ON DOGS 



By M. H. ROSS and J. O. ELY 



Reports on the severe clinical and chemical effects of an instantaneous 

 massive dose of all of the known types of penetrating radiation on human 

 beings (1) indicated the importance of further study of the changes induced 

 in living tissue. Laboratory studies on the biological effect of neutron 

 radiation indicated that the hematopoietic (2) and spermatogenic tissues 

 (3) and the tissues of the gastrointestinal tract (3) are profoundly' affected. 

 In order to study the clinical, pathological, hematological and blood chem- 

 ical changes associated with large doses of neutron radiation, four dogs, 

 available from other work, were used in the following investigations. 



Two adult male and 2 adult female dogs of mixed breeds were given 

 a total of 400 n during 4 consecutive days: 115 n on the 1st, 2nd and 3rd 

 days and 55 n on the 4th day. The rate of administration, in Box No. 4, 

 was approximately 18 n per hour (4). 



The dogs had free access to water at all times. They were fed once a 

 day and allowed at that time all the food (Friskies) they desired. The 

 average daily food consumption for the 21 day pre-irradiation period was 

 8 oz. per dog. During the post-irradiation period the food was available 

 for 4 to 5 hours each day. 



Clinical Effects. No food was consumed after completion of irradiation. 

 During the 4 days required to administer the irradiation, the average daily 

 food intake was 2 oz. per dog. 



The average weight of the dogs decreased rapidly following irradiation. 

 Water intake was decreased ; the dogs became dehydrated, cachectic, phleg- 

 matic and weak and, shortly before death, comatose. Two of the 4 dogs 

 had foul breath. Both of these dogs had gray, necrotic ulcers in the mouth. 

 The skin was dry, the hair coarse, rough and lustreless, and the skin and 

 hair had a peculiar odor. Before death 2 of the dogs passed thick, mucoid, 

 bloody feces. One dog vomited 1 day before death. One dog died 6 days, 

 one 7^ days, and one 8 days following completion of irradiation. The other 

 one was killed on the 7th day. 



No blood pressure measurements were made, but great difficulty was 

 experienced in obtaining blood from the radial vein of the forearm after 

 completion of irradiation, indicating a reduced venous blood pressure. A 

 reduced blood pressure was also indicated by a weak and rapid heart action. 



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