l'->^"] VETERINARY MEDICINE. 385 



vlrult'iil ;iii(I r» (lavs did vifiilciit. Slalilc Hies did nut Iraiisiiiit Ihvu cliolcra 

 virus. 



A hactoriolof^ical study of lio.i,' clinlcni hlnod sliowcd the jji-cseiico <d" J'tiriUii'i 

 suilKntifvr in "> out of S cidtuivs, atypical li. aniiir.stifcr in 2, and J{. pantlj/pho- 

 stis B iu one cuUuiv. Of tlie 9 cultures isolated Ironi the tissues of raltbits 

 tiiat liad l)een inoculateil with lios cliolera blood, 5 proved to be B. mtipcsiifer, 

 1 li. paratiiphomiH A, 2 B. para typhosus B, and 1 B. paratyphosus B interinedi- 

 aU'. A study of 200 cultures of bacteria isolated from hof?s that had succunil)ed 

 In so-called "mixed infection" indicated that B. suipcsiifcr predominated in 

 Ihe body tissues and B. coli in the intestines. The inoculation of suscctttible 

 pifjcs with l)lood collected from sick lio<rs in 14 outbreaks which did not have the 

 characteristic syniptonis of hoj,' cholera produced typical hoj? cholera in 7 

 cases. Four of the blood samples that were not pathogenic to liofis, rabbits, 

 and {ruinea pijrs were from hofis showing extreme hemorrliagic lesions on post 

 mortem. 



The section on swine diseases also includes brief I'eports of work on hemor- 

 rhagic septicemia, swine plague, and swine dysentery. 



IOxi)erinii'nts relating to hog cholera serum i)roduction are reported which 

 indicate that virus blood from hogs killed 7 and 8 da.vs after inoculation does 

 not produce a more potent serum than that produced with virus blood from hogs 

 killed from 4 to 6 days after inoculation. Elevation of body temperature (106 

 to 108" F.) is thought to be" a safer guide in virus blood production than fatal 

 symptoms or extreme cholera lesions. Negative results were obtained in at- 

 tempts to correlate the presence of gas-producing bacteria in cholera blood virus 

 with los.ses following hyperiumiunization of hogs. 



The report also includes a brief statement regarding the investigatioi\ of 

 forage itoisoning, and data on the laboratory diagnoses conducted by the dei)art- 

 ment, and on the production and testing of hog cholera serum during the year. 



Hog cholera (Xorth Dakota ma. Bnl. 136 {lim), p. 22).— Experimenls to 

 determine tlu' effect of the passage of hog cholera virus through foreign species 

 of animals are reported. In the case of peccaries the virus remained active for 

 susceptilde pigs through four passages but after the fifth passage lost its viru- 

 lence. With goats the virulence was destroyed after two passages and with 

 rabbits after one. Neither peccaries, goats, nor ral»bits contracted the disease, 

 nor did the virus increase in potency in passage through these species. 



Experiments to deternune the minimal lethal dosage of virus for susceptible 

 pigs indicated that quantities as small as 0.(X)5 cc. and 0.0025 cc. of potent virus 

 will produce the disease. In dialysis experiments the virus failed to dialyze 

 iu either 0.8o per cent NaCl solution or in distilled water. 



Muligiiuiit edema in swine, F. ruoKsciiKit and H. A. Hoffman {Amer. Jour. 

 Vet. Med., 15 {l'J20), No. 6, pp. 2J)7-25], fign. //).— While this affection, due to 

 BaciUiis wdcmatis mali(/ni, has seldom been recorded as occurring in swine, the 

 authors' experience in Iowa indicates that it is more prevalent than is gener- 

 ally recognized. 



The disease in swine appears to have usually been diagnosed as a form of 

 septicemia of unknown origin. The authors have observed a considerable num- 

 ber of pigs at the Sioux City .stockyards which succumbed to this disease inuue- 

 diately following serum sinuiltaueous vaccination for hog cholera. A report of 

 a similar loss from this affection is said to have been received from Nebraska, 

 the dia^^osis having been confirmed by bacteriological exanunation. 



An account is given of an outbreak which occurred in a serum i)lant in which 

 an antitoxin serum was protlucMl by innnunizing the pig with increasing doses 

 of the toxin. The organism isolated was found to represent a new variety. 

 This serum protected guinea pigs against a nmltiple fatal does of the toxin. 



