The floating method was carried out with 7 graded solutions of zinc sulfate ranging from 1.05 to 1.40 in specific gravity (SP). Samples were collected from the contents of every portion of the intestine, as well as feces. When eggs were preserved at 20°C for 2-4 hours' the rate of eggs floating in solutions 1.20-1.40 in SP ranged from 80 to 94%. When canine hookworm eggs were exposed to direct sunlight for 40 minutes, they gave a remarkably low rate of floating in solutions 1.20-1.40 in SP
Two groups, 1 and 2, of hogs fed garbage and a formula diet, respectively, were examined histopathologically after slaughtered. Samples were collected. from the musculus geniohyoideus (A), m. sternohyoideus (B), muscular portion of the diaphragm (C), and m. obliquus externus abdominis (D), fixed in 10% formalin, and stained with hematoxylin and eosin. Degeneration was found in 29 hogs (76%) of 38 of group 1 and in 35 hogs (92%) of 38 of group 2. The positive rate of degeneration in muscles A, B, C, and D was 59, 61, 44, and 68% respectively, in7group 1 and 58, 76, 72, and 65%, respectively, in group 2. It was 55% in hogs affected with some visceral disorder and 64% in hogs free from such disorder in group 1, and 65% in affected hogs and 72% in'healthy hogs in group 2.
Pseudomembranous laryngortacheitis broke out in the same swine herd in May, 1972, and May, 1973. Finally, 12 suckling piglets were affected with it among 43 piglets of 5 litters. Of them, 5 piglets died of the disease. Clinical observation revealed an increase in nasal discharge about 10 days of age and marked dyspnea at 15 days of age, when the severely affected animal died from suffocation. Sucklings showing good growth were ready to contract the disease. Contact infection was observed. Natural recovery seemed to take place by 40 days of age. Histological examination revealed exudative rhinitis, bronchopneumonia, and pulmonary emphysema in addition to pseudomembranous laryngotracheitis. Corynebacierium pyogenes was isolated from three cases and C. psoidopyogenes from one case.