Monitoring and management of mountain environment.

The monitoring of mountain environment gives necessary information for its control and effective management in view of its sustainable development. A system of complex monitoring of environment has been established, including physical, chemical, meteorological, hydrological, biological and sociological factors. Methods and observations have been developed and applied. Using a geographical information system, a database was created for Rila Mountain and a modern computer network connected to internet was established. As a direct consequence of the French-Bulgarian project OM2 (carried out in the period 1993-1998) a Basic Environmental Observatory (on the peak Moussala, 2925 m) was constructed and put in operation in attempt to control the large scale and long-term transportation of atmospheric pollutants.

[Pathology in hybrid pig breeding due to mixed infections]. / Patologiia na khibridnoto svinevudstvo, prichineno ot smeseni infektsii.

A total of 7,500 samples from 5 swine breeding complexes with 200,000 hybrid Camborough pigs were studied morphologically and bacteriologically. The raising technologies used on all complexes were of industrial type or semi-industrial and extensive. A description is given of the simultaneous participation of the following nosologic units: colibacteriosis, responsible for 13 to 14 per cent of the total mortality rate in newborn pigs; bronchopneumonia--causing 6 to 39 per cent losses in the other age groups; and dysentery with salmonellosis--inflicting 5 to 9 per cent losses. Underlined is the great advantage of the industrial technologies of animal raising as against the conventional ones in the prevention of these diseases in hybrid pig breeding. Tested were effective programmes for the prophylaxis associated with the individual nosologic units. More essential were the following: active immunoprophylaxis with live attenuated vaccines against colibacteriosis and salmonellosis; elimination of the alimentary stress factor in dysentery; disinfections of premises by gassing with a mixture of ammonium nitrate and chlorinated lime in a 1:2 ratio. However, all measures proved effective when the principle of "all in, all out' was observed which is essential part of the Camborough industrial raising technologies.

[Diseases of the locomotor apparatus in pigs on commercial farm complexes]. / Prouchvane na zaboliavaniiata na stavnodvigatelniia aparat pri praseta v promishlenite kompleksi.

This type of affections concern mainly pigs in the first several days following birth, and rarely pigs up to the age of 15 to 20 days. Their manifestation has a stationary character. They are encountered more frequently and on a mass scale in the winter and spring months. The carpus joints are chiefly affected, whereas the distal joints of the hind legs are much more rarely involved. Detailed epizootiologic, bacteriologic, clinical, haematological, biochemical, and X-ray investigations have been carried out with normal and diseased pigs and the respective sows. The disease process has been found to develop under the influence of occasionally pathogenic pigsty microbial flora, which entered the body most often through the affected skin of the knee joints when sucking. Laboratory studies revealed that Staphylococcus hyicus took part. Carriers of the infection were the sows from which the same causative agents were isolated. Biochemically, a lowered level of the serum calcium was demonstrated, accompanied by well defined leukocytosis in the more strongly affected pigs and their sows. It was shown that in terms of prophylaxis most effective were the local treatments of the diseased knee joints of pigs in the first three days after birth with granulin as well as the treatment of the sows and their offsprings with antibiotics, vitamins, and calcium preparations. It was shown that the regular and opportune disinfection with 1-2 per cent sodium hydroxide was of special interest.

[Pathomorphological changes in colibacteriosis in pigs]. / Patomorfologichni izmeneniia na kolibakteriozata pri praceta.

A total of 46 suckling piglets spontaneously affected with colibacteriosis and 20 pigs aged from 1 to 10 days, experimentally infected with two strains of Escherichia coli (0149 and 0138) were investigated morphologically. Both in the animals with spontaneous infection and in those with experimentally induced disease there were severe morphologic lesions not only in the small intestines, but also in the other viscera and the brain. Catarrhal to hemorrhagic enteritis was observed in 56.5 per cent of the spontaneous cases and 57.1 per cent of the test animals. Parenchymal dystrophy with hemorrhages were seen in the liver in 89.1 per cent of the pigs of the first group and 57.1 per cent of those of the experimental group. Kidney lesions were noted in 65.2 per cent and 28.6 per cent, respectively. Spontaneously affected piglets showed bacterial thrombi in the lumen of some small blood vessels, and in the adrenals (23.9 per cent) and the thymus (13.00 per cent). In the brain there was meningoencephalitis in 54.3 per cent of the spontaneously affected animals and in 85.9 per cent of the experimentally infected ones. In the test animals infected with serotype 0149 there were more serious morphologic changes than in those infected with serotype 0138. It was demonstrated that occasionally pathogenic E. coli organisms had a broader spectrum of action in the body of host sucklings. So colibacteriosis is considered a severe generalised disease which runs its course in sucking pigs as septicaemia and toxaemia.

[Viral carrier state and viral excretion in classical swine fever]. / Prouchvane vurkhu virusonositelstvoto i virusootdelitelstvoto pri klasicheskata chuma po svinete.

Studies on swine pest virus carrying and elimination on swine vaccinated by lapinizated vaccine strain "K" from rabbits were performed. Vaccinated swine were injected with the pathogenic virus on the 60th day post vaccination and to them were added not immunized swine with the aim to discover virus elimination. The experimental swine were decapitated on the 3, 5, 6 and 7th day post infection. Alternating passages were made by emulsion of the inner organs of these swine on not immunized swine as well as pathohistological investigation of the parenchymal organs and the brain. Presence of the virus and of pathohistological changes were not detected 7 days post injection of the virulent virus. Contact having swine which served as a indicator for virus elimination were observed for 21 days, but remained healthy. These swine, when infected with the virulent virus, suffered from pest.

[Atrophic rhinitis in swine]. / Prouchvaniia na atrofichniia rinit po svinete.

Four 60-day-old pigs were experimentally infected with Bordetella bronchiseptica at a state in which the animals were clinicylly normal. A single pig only, killed on the 180th day, presented a slight deflection of septum nasi. Morphologically, there were severe dystrophic and necrotic changes in the mucosa of the conchae, the nasal cartilages as well as in the bones. The pathogen was reisolated from two of the pigs. Clinical and morphological investigations were carried out also with spontaneously affected animals, isolating Pasteurella multocida, Pseudomonas aeruginosa, and Mycoplasma organisms, but not Bordetella bronchiseptic. Morphologically, there were in 37 of the pigs severe dystrophic and necrotic lesions in the nasal mucosa, cartilages, and bones. Basophilic inclusion bodies were demonstrated in the epithelial cells of the tubulous glands. It is concluded that a combined method of prophylaxis and treatment would be most effective, and of the drugs borgal has proved likewise most promising.

[Studies of the etiology of cystopyelitis in hybrid swine]. / Prouchvaniia vurkhu etiologiiata na tsitopielitite po khibridnite svine

Studies were carried out on the etiology, clinical picture, morphologic changes, and methods of prophylaxis of the cystopyelitis in hybrid pigs. It was established that in the cases studied the etiologic part is most probably played by Escherichia coli having pronounced virulence for albino mice. Clinically the disease was manifested with hematuria--the cardinal diagnostic symptom; histologically there were nephritis, pyelonephritis, and strong edemas on the wall of the bladder. When hematuria appeared the affected pigs died (at the rate of 100 per cent) as a result of acute anemia. Prophylactic measures have been especially successful with the use of streptomycin to which the isolated coli strains proved sensitive.

[Studies of the carrier state and excretion of the pathogenic plague virus in vaccinated swine]. / Prouchvaniia vurkhu nositelstvoto i izluchitelstvoto na patogenniia birus na chumata pri vaksinirani svine

Investigations were carried out on the presence of carriers and the excretion of the virulent swine fever virus in pigs vaccinated with the lapinized vaccine strain K. On the 15th, 25th, and 35th day following injection with the virulent virus a pig was killed each time and material was taken for morphologic studies and immunofluorescence microscopy. The results of the investigations were negative except for two pigs the cerebrum of which showed perivascular, slightly to moderately expressed lymphoid-cell agglomerations as well as a weakly manifested perivascular edema. Material of the killed animals was used to infect unvaccinated susceptible pigs in which the presence of the virus had not been demonstrated. No clinical and morphologic data or immunofluorescence microscopy demonstration proved the presence of a virus upon exposure of animals to pigs that were injected with a virulent virus. Hematologic studies revealed leukopenia, lower percent of hemoglobin, and a drop in the erythrocyte count following injection with the virulent virus. After a certain period of time this condition was overcome. These experiments showed that when a virulent virus gains access to pigs that have become immune after vaccination with the K vaccinal strain of the swine fever virus does not persist longer than the seventh day and does not cause the development of latent or a clinically manifested infectious process.