Seven dogs 3 to 8 years old manifested such clinical symptoms as a rise in body temperature, anorexia, depression, lameness, astasia, and paralysis or hyperesthesia of the hind quarters. Of them, two took an acute course of 2 and 7 days, respectively, and five a subacute course of 20 to 115 days. Four dogs were subjected to hematological examination, urinalysis, electrocardiography, phonocardiography, radiography, and determination of circulation time. As a result, they showed an increased leukocyte count and radiographic changes of embolism of arteries in the hing quarters, in addition to the ordinary findings of canine filariasis. The other three dogs were in so severe conditions that they could be examined by no tests, except one which demonstrated that they were positive for microfilariae, in blood. From these results, all the dogs were diagnosed as paradoxical embolism induced by canine filariae. Autopsy revealed that an open condition of the ductus arteriosus (3.5 cm in diameter and 2.4 cm in length) was present in one dog and an open condition of the foramen ovale (from a pin-hole size to about 1 cm in diameter) in the other dogs. Embolism caused by canine filariae was observed in the femoral artery in all the dogs and in the abdominal or thoracic aorta and the renal artery in two dogs.
Of 137 chickens handled in some processing plants, 16 (11.6%) were proved to be Salmonella carriers. The amount of organisms harbored was generally large in the skin and viscera and small in feathers. There was a tendency that the contamination rate increased with the advance in the meat processing in the plant, although the amount of contaminating organisms was small. Salmonella sofia was the most prevalent of six types detected. A tendency was shown that the type and pattern of drug resistance of Salmonella distributed in the living bird, carcase, and apparatus of rcmoving feathers varied from one processing plant to another.
Five trials were carried out with more than 15, 000 chickens, including approximately 10, 000 birds inoculated with Marek's disease vaccine (Deptavac-HVT). Each trial lasted for 180 days. The disease broke out in 7.5% of the vaccinated birds and 14.4% of the unvaccinated control ones. The rate of decrease in outbreak of the disease in the vaccinated birds was 48.1%. Death and culling occurred from a variety f causes, including weakness accidental death, cannibalism, Marek's disease, leucosis, and chronic respiratory diseease. There was no significant difference in positive rate for gel-precipitating antibody against Marek's disease, mean titer of neutralizing antibody against infectious bronchitis virus, or positive rate for agglutination againstMycoplasma gallisepticunzbetween the vaccinated and control groups. When some vaccinated birds were subsequently inoculated with killed or live Newcastle disease vaccine 2 to 4 times during a period from 4 to 143 days of age no hemagglutinatio-ninhibiting antibody response to this vaccine was suppressed in any of 4 vaccinated groups.
Effect of preventing clinical Marek's disease (MD) was compared among frozen vaccine prepared from the low virulent C2 strain originated from MD herpes virus (MDHV) developed by the Osaka University Microbiological Disease Laboratory, frozen and freezedried vaccines prepared from the Ol strain of HV of turkey (HVT), and frozen vaccine tentatively prepared from HVT originated from sonie overseas laboratory. Commercial White Leghorn chicks were used. When examined by the indirect fluorescent antibody technique, they had an anti-MDHV FA titer of 1: 1590 and an anti-HVT FA titer or 1: 470. They were inoculated intraperitoneally with vaccine at one day of age and challenged by the same route at 3 weeks of age. Chicks inoculated with the same vaccine were held in the same house separately from chicks inoculated with any other vaccine. Results were judged histopathologically in all the birds at about 20 weeks of age. In conclusion, there were no differences in the effect of prevention among the four vaccines. Besides, it was confirmed that a freeze-dried vaccine prepared from cell-free HVT showed a satisfactory effect even when inoculated into chicks possessing a ratherhigh level of maternal antibody.