XI. PATHOLOGY 567 



producing diets^- '" were undoubtedly due to concomitant riboflavin defi- 

 ciency as shown by Sebrell and associates." Smith ei al.^^ were apparently 

 the first to note the large number of fuso-spirochetal organisms in the 

 mouths of blacktongue dogs. The almost universal occurrence of this 

 Vincent's-type infection is one of the most puzzling features of canine 

 blacktongue. 



Nicotinic acid deficiency may occur in dogs without blacktongue, espe- 

 cially in puppies and when purified diets are used.^^ Handler and Dann^* 

 found that dogs could be cured of blacktongue by treatment with intra- 

 venous saline only to continue to lose weight and develop a severe anemia 

 and leucopenia (p. 564). The bone marrow of such dogs has not, apparently, 

 been studied. 



2. Hogs 



Miller and Rhoads^^ fed swine a modified Goldberger diet and observed 

 a syndrome similar but not identical to blacktongue in dogs, i.e., stomatitis, 

 achlorhydria, anemia, diarrhea, loss of appetite, and weakness. Both macro- 

 cytic and microcytic anemias were observed. These deficiency symptoms 

 could be relieved with oral or parenteral fiver extract. Several other in- 

 vestigators gave similar diets and observed the beneficial effect of nicotinic 

 acid on the deficiency state. ^^"^'' Braude et al}^ used Chick's diet^^ and made 

 a study of the gross pathology of pig pellagra. In their experiments, the 

 pigs had a rough, "staring" coat but showed no actual dermatitis. Several 

 pigs had small ulcerations of the buccal mucosa and most had a severe 

 enteritis with necrotic ulceration of the cecum and large bowel. Fibrinous 

 pleurisy, mild anemia, and, frequently, pneumonia were found in animals 

 which died of the deficiency. 



Unfortunately, most of the experiments referred to above were undoubt- 

 edly complicated by deficiencies of nutrients other than nicotinic acid. 



» W. H. Sebrell, Natl. Insts. Health Bull. 162, 23 (1933). 

 1° W. H. Sebrell and R. D. Lillie, Natl. Insts. Health Bull. 162, 37 (1933). 

 " W. H. Sebrell, R. H. Onstott, and D. J. Runt, Public Health Repts. (U.S.) 52, 



427 (1937). 

 12 D. T. Smith, E. L. Persons, and H. I. Harvey, J. Nutrition 14, 373 (1937). 

 " P. Handler, Z. Vitaminforsch, 19, 393 (1948). 

 " P. Handler and W. J. Dann, J. Biol. Chem. 145, 145 (1942). 



15 D. K. Miller and C. P. Rhoads, /. Clin. Invest. 14, 153 (1935). 



16 H. Chick, T. F. Macrae, A. J. P. Martin, and C. J. Martin, Biochem. J. 32, 10, 844 

 (1938). 



1^ E. H. Hughes, Hilgardia 11, 595 (1938). 



18 L. C. Madison, R. C. Miller, and T. B. Keith, Science 89, 490 (1939). 



" M. M. Wintrobe, Am. J. Physiol. 126, 375 (1939). 



2° A. N. Worden and G. Slavin, /. Comp. Pathol. Therap. 54, 77 (1944). 



21 R. Braude, S. K. Kon, and E. G. White, Biochem. J. 40, 843 (1947). 



