[Specific prophylaxis of gangrenous mastitis in sheep]. / Spetsifichna profilaktika na gangrenozniia mastit po ovtsete.

Staphylococci were isolated from the udder of dead sheep and sheep that were emergency-slaughtered because of a gangrenous mastitis infection. The organisms proved to be hemolytic and mannite- and catalase-positive, and were referred to various phage types, being most frequently lysed by phages 78 and 42E. Toxin production depended on the quality of the medium used, the amount of atmospheric carbon dioxide, the period of incubation, and the individual strain qualities. Strains of high hemolysin production were used to prepare a vaccine which was applied to sheep both experimentally and in the conditions of the practice at the time of active lactation. Following treatment of the vaccinated animals parallel to a number of controls with one and the same challenging agent morbidity with the first group ran as high as 25 per cent with no death cases, while with the second group it was 100 per cent, and mortality with the latter was 50 per cent. Immunity with the use of the vaccine lasted but four months, therefore, revaccination was needed by the end of this period.

[Anaerobic dysentery in pigs]. / Anaerobna dizenteriia pri praseta.

Anaerobic dysentery (necrotic enteritis) of sucking pigs was demonstrated on an industrial swine-breeding farm. The disease was found to be caused by Clostridium perfringens, type C, and attacked up to 3 per cent of all sucking pigs at the age of 1 to 5 days, mortality rate ranging as high as 50 per cent. Outbreaks were recorded only in boxes fixed on the floor of the premise itself. The control of the disease made use of complex measures, including washing of sows with disinfection solution prior to their accomodation in the farrowing unit, strict observation of the principle 'all in, all out', feeding medicated premixes to the sows, improved hygiene on the premise, vaccination of the sows with an antiperfringens vaccine, and oral treatment of the diseased pigs prior to sucking with a specific hyperimmune antitoxic serum as well as using broad-spectrum antibiotics, spectinomycin, and pharmazin. With all measures applied the disease was fully suppressed.

[Respiratory diseases in sheep due to Mycoplasma ovipneumoniae]. / Prouchvaniia vurkhu respiratorni zaboliavaniia po ovtse s uchastie Mycoplasma ovipneumoniae.

Mycoplasma ovipneumoniae was isolated from sheep and lambs affected with a respiratory disease. It was established that the pneumonic disease caused by this organism was a severe one, with high mortality rate in young lambs. Adult sheep and older lambs remained chronically affected. Susceptibility varied, depending on the breed of the animals, some imported animals running a more severe course of the disease than the local ones. The disease was artificially induced in lambs at the joint infection with M. ovipneumoniae and P. haemolytica. The morphologic changes in the lungs consisted in a prevailing proliferation of the septal cells and polynuclear cells in the alveoli, an interseptal histiocyte proliferation, and a serous leukocyte infiltration.

[Method of controlling live vaccines against listeriosis]. / Metod za kontrol na zhivite vaksini protiv listerioza.

Used was Anton's conjunctival test with guinea pigs to control the actual immunogenicity and innocuity of a live vaccine against listeriosis. It was found that local immunity could be produced following a successive conjunctival infection only, initially with the use of a listeriosis vaccine and in not less than ten days later with pathogenic strains of the respective serotype. The method makes it possible to carry out both titration and control on the equal volume ratio of the vaccinal strains of the two serotypes in the vaccine.

[Respiratory enzootics in sheep caused by Pasteurella haemolytica]. / Prouchvane vurkhu respiratornite enzootii pri ovtsete, prichineni ot Pasteurella haemolytica.

Bacteriologically in 25 per cent of the materials taken from lambs, weaned lambs, and adult sheep Pasteurella haemolytica was invariably isolated. Serologic typing revealed that serotypes A2 and A6 were mostly widespread. The remaining serotypes proved to be encountered. Widely occurring were likewise the carriers of Pasteurella haemolytica both among the diseased animals and among the normal contacts--30 and 6 per cent, respectively. The serotype of the isolated strains (swab samples) was shown to be identical with the serotype of the strains isolated from pathologic materials on the same farm. This spoke of the symptomless existence of the infection in the flock and the important part played by such stress factors as movement, transportation, etc. in the outbreaks and the aggravation of the P. haemolytica infections. The isolated strains were apathogenic for albino mice and were sensitive in vitro penicillin, chloramphenicol, tetracycline, and streptomocin.

[Biochemical properties of different serotypes of Pasteurella haemolytica]. / Biokhimichni svoistva na razlichnite serotipove Pasteurella haemolytica

Studied were the morphologic and biochemic properties of 85 Pasteurella haemolytica strains belonging to the known 12 serotypes after Biberstein, Gills (2). The biochemical properties of the strains were studied after the pattern of Bosworth and Lovell (4) with regard to arabinose, trehalose, xylose, manose, salysin, and lactose. It was found that the biochemical properties correlated with the biotype classification of the strains. Thus, the biochemical reaction with trehalose and arabinose may be used as a characteristic feature in determining the biotype. The reaction proved more dependable with the strains of the T biotype as compared to those of the A biotype, as not all strains of the A biotype fermented arabinose in the course of the first seven days, while with the strains of the T biotype trehalose was acted upon during such a period. It was also established that xylose is attacked by the strains of the A biotype only, and manose and salycin--by the strains of the T biotype, which did not ferment lactose. All strains of Pasteurella haemolytica turned out to be negative so far as the production and indol was concerned; they were shown to reduce the nitrates into nitrites, were MP and VP negative, and gave growth in McConkey's agar medium.

[Serologic typing of strains of Pasteurella haemolytica isolated from sheep]. / Serologichno tipizirane na shtamova Pasteurella haemolytica, izolirane ot ovtse

Typed were a total of 85 strains of Pasteurella haemolytica isolated from lambs, weaned lambs, and adult sheep in cases of septicemia and broncho-pneumonia applying the hemagglutination-inhibition reaction and making use of capsule antigens and anti-capsule hyperimmune sera. It was found that 74 strains belong to biotype A, five belong to biotype T, and six remained untyped. Most wide spread in this country proved serotype A2--35 strains, followed by serotype A6--14 strains.