Bulgarian Journal of Veterinary Medicine (BJVM)
ISSN 1311-1477
Bulgarian Journal of Veterinary Medicine
VOL. 5, No 1, MARCH, 2002
CONTENTS
1
19
I. Chenchev and S. Martinov
Epizootological situation of equine influenza23
T. P. Popova and Y. M. Tzvetkov
Fowl cholera in pheasants (Phasianus colchicus) etiological investigation and effect of therapy with thiamphenicol29
P. Prelesov, D. Gundasheva and N. Groseva
Haematological changes in chickens, experimentally infected with biting lice (Phthiraptera-Insecta)39
S. Stoyanov, S. Martinov and N. Bildirev
Survey on the incidence and nature of some obstretical and gynecological problems in cows, bred in large and small private farms47
55
D. S. Dimitrov, K. V. Hristov and A. Angelov
Some season-related morphometric, structural and weight characteristics of testes in the viper (Vipera ammodytes)61
N. Takuchev and k. vassilev
territory-determined factors influencing the enrolment of veterinary medicine students69
in memoriam
Published by the Trakia University, Faculty of Veterinary Medicine,
6000 Stara Zagora, Bulgaria
Volume 5, Number 1, March 2002, Summaries
Hadjiev, G., 2002. Studies upon the basic characteristics of avian paramyxovirus type 1 strains, isolated from pigeons in Bulgaria. Bulg. J. Vet. Med., 5, No 1, 1-18.
The basic characteristics of 3 avian paramyxovirus type I (A/PMV-1) strains, isolated from domestic pigeons in Bulgaria, were paralelly studied with reference strains of the Newcastle disease virus (NDV) belonging to all pathotypes. According to generally accepted standard biological tests, the strains from pigeons referred to the mesogenic pathotype of NDV. According to their plaque forming ability in primary monolayer cell cultures of chicken embryo fibroblasts (CC/CEF) under agar cover, the local strains from pigeons behaved like velogenic NDV strains. Pigeon strains showed a high agglutination activity against chick erythrocytes and their haemagglutinins were stable at 56oC. NDV-sensitive chickens, aged 5-8 weeks, inoculated intramuscularly, intravenously, intracloacally or intraconjunctivally with local A/PMV1 strains, obtained from pigeons as well as non-infected chickens from the same batch, put in contact with infected ones, developed an occult infection. Both inoculated and contact chickens underwent an immunological transformation they reacted with formation of high titres of specific serum antibodies that protected them from disease or death after challenge with a definitely lethal dose of a velogenic-viscerotropic NDV strain. Our previous studies upon Bulgarian A/PMV1 strains isolated from pigeons did not suggest that they were really dangerous for poultry health by respect to Newcastle disease. This statement is supported by other observations in the country as well.
Key words: Newcastle disease, paramyxovirus type 1, pigeon
Chenchev, I. and S. Martinov, 2002. Epizootological situation of equine influenza. Bulg. J. Vet. Med., 5, No 1, 1922.
The first epizootic of equine influenza in Bulgaria was in 1978 while the last one was identified in 1989-1992. The virus that caused the last epizootic in Bulgaria was antigenically related to the A2 Miami 1/63/H3N8/ strain. After a screening serological examination of equine population, it was established that antibodies against the A2 Miami 1/63 /H3N8/ serotype were the commonest while those to the A1 Prague 1/56 /H7N7/ serotype were less in the absence of vaccination. The respective percentages against A2 Miami 1/63 /H3N8/ in 1999 were 59% in adult horses and 56% in mares.
The situation among the equine population concerning influenza as well as the necessity for a preventive program for its control were established.
Key words: haemagglutination inhibition, influenza, serotypes A1 and A2
Popova, T. P. and Y. M. Tzvetkov, 2002. Fowl cholera in pheasants (Phasianus colchicus) etiological investigation and effect of therapy with thiamphenicol. Bulg. J. Vet. Med., 5, No 1, 2328.
In an outbreak of fowl cholera that occurred in a pheasant (Phasianus colchicus) flock, seventeen per cent of about 1000 birds from the flock died of an acute disease. The established pathological alterations were typical of fowl cholera. Pasteurella multocida was isolated in pure culture from hearts, livers and spleens of three dead birds. Examined characteristics included phenotypic and biochemical determination of the biotype (subspecies) and the in vitro susceptibility of isolates to antimicrobial agents. Isolates were identified as belonging to the multocida subspecies. Their drug susceptibility was identical. All isolates were highly susceptible in vitro to tested amphenicols, including thiamphenicol. The application of thiamphenicol in the drinking water stopped the mortality.
Key words: antimicrobial therapy, fowl cholera, pheasants
Prelezov, P., D. Gundasheva and N. Groseva, 2002. Haematological changes in chickens, experimentally infected with biting lice (Phthiraptera-Insecta). Bulg. J. Vet. Med., 5, No 1, 29-38.
The aim of the study was to determine the haematological changes in chickens, experimentally infected with biting lice from the following species: Eomenacanthus stramineus Nitzsch (1818), Menacanthus cornutus Schömmer (1913), Menopon gallinae L. (1758) and Goniocotes gallinae DeGeer (1778). The experiments were performed on 30 (20 experimental and 10 control) 2-month-old chickens (Gallus gallus domesticus).
The infection with biting lice resulted in reduction in red blood cell (RBC) counts and haemoglobin content, increase in the mean corpuscular haemoglobin (MCH), the mean corpuscular haemoglobin concentration (MCHC), the mean corpuscular volume (MCV) and the haemoglobin index (HbI), indicating the development of a hyperchromic anaemia. The white blood cell (WBC) counts were elevated as well as the percentages of eosinophils and monocytes following activation of the innate defense mechanisms. Lymphocyte percentages were lower. Both qualitative and quantitative haematological changes observed in chickens, infected with biting lice, were the highest during the period of most intensive invasion (September).
Key words: anaemia, biting lice, chickens, Mallophaga, Phthiraptera
Stoyanov, S., S. Martinov and N. Bildirev, 2002. Survey on the incidence and nature of some obstretical and gynaecological problems in cows, bred in large and small private farms. Bulg. J. Vet. Med., 5, No 1, 39-46.
As a result of the structural reform in livestock breeding in Bulgaria during the last years, the relative part of small private farms has increased. The expectations that obstetrical and gynaecological problems would diminish under these new conditions were not justified and thus, motivated the necessity to clarify this problem from a scientific point of view and to develop measures to address it.
The present survey have studied and analyzed some reproduction problems in cows, bred in small farms using data for 302 cows in 35 farms situated in the western part of the country and the methods of clinical gynaecological examinations, statistics and analysis.
The analysis of the reproductive status of the cows indicated a high percentage of infertility (an average of 41.7%), which was unfavorable to the future reproduction process. The average percentages for recently inseminated cows were 22.5% and for the recently calved 16.5%, while the percentage of pregnant cows (19.2%) was extremely unsatisfactory. The presented data showed deviations from the accepted standard indices, of a satisfactory fertility and productivity. The indices, characterizing the relative part of dystocia (16%), retention of the placenta (about 18.7%) and endometritis (about 30%), were all unsatisfactory when taking into consideration the standards set for an optimal reproduction process. The aforesaid data were a prerequisite for chronic endometritis and functional disorders.
Key words: cows, fertilization, gynaecological disorders, infertility, obstretical disorders, reproduction
Dinev, I., 2002. Clinical and morphological studies on spontaneous myelocytomatosis in layer-hens associated with other neoplasms. VIII. Haematological and morphological studies of peripheral blood and bone marrow. Bulg. J. Vet. Med., 5, No 1, 47-54.
The results of haematological and morphological investigations of peripheral blood and bone marrow in a flock of 1620 White Hissex layer hens aged 7-15 months with enzootic myelocytomatosis (MC) associated with other neoplasms, are presented. In part of the birds, only MC lesions were clinically and morphologically established; in another part MC lesions occurred together with other neoplastic types and in a third - various types of neoplasms without MC lesions.
Haematological studies were performed in 78 birds with clinical signs or suspicious for neoplasia. The average values of haemoglobin and blood cell counts - erythrocytes, leukocytes and thrombocytes were determined. Bone marrow specimens obtained from the tubular bones (femur and tibia) of all hens included in the investigation, were histologically studied.
In MC birds as well as in those with a simultaneous occurrence of MC and other neoplasms, a considerable decrease in all haematological values, poorer haemapoiesis and increased extrasinus myelopoiesis in bone marrow were present. The appearance of immature cell from the granulocytic rank was observed.
In hens with tumours without MC lesions, there were no significant deviations from the normal haematological picture and bone marrow histostructure.
Key words: avian leukosis, avian leukosis viruses, myelocytomatosis, neoplasms, poultry
Dimitrov, D. S., K. V. Hristov and A. Angelov, 2002. Some season-related morphometric, structural and weight characteristics of testes in the viper (Vipera ammodytes). Bulg. J. Vet. Med., 5, No 1, 55-60.
The study was performed on testes, obtained from 14 vipers (Vipera ammodytes), inhabiting various regions of Bulgaria, collected during the four seasons of the period 1996-1999 inclusive. The weight and the macrometric parameters of testes were measured. The outer diameter of seminiferous tubules and season-related microstructural features were determined via light microscopy. Data from weight, metric and micrometric measurements were statistically processed. Their analysis showed that from winter to the end of spring (when the breding period of vipers in Bulgaria occurs), the weight of testes increased more than thrice, the diameter of seminiferous tubules - more than twice and afterwards the values of both parameters decreased gradually and reached the highest values for the winter season by the end of the autumn. The seasonal variations in both weight and diameter correlated with the histological status of testes. The involution processes within seminiferous tubules, starting by the beginning of winter, were still active also in the middle or end of spring, when vipers were ready again for another reproductive period.
Key words: season-related characteristics, testes, viper
Takuchev, N. and K. Vassilev, 2002. Territory-determined factors influencing the enrolment of veterinary medicine students. Bulg. J. Vet. Med., 5, No 1, 61-68.
The factors, influencing the enrolment of veterinary medicine students from all regions of the country were studied using statistical methods and data for students, admitted in the Trakia University Stara Zagora. By the method of step regression, the impact of 3 out of 11 studied factors was outlined. Their correlation coefficients with the number of students from a given region were as followed: popularity of the speciality (0.812), population of the respective region (0.462) and distance to the educational centre ( 0.347).
The dependance of the total score of admitted students and the grades included in the score was also studied. A low correlation of the total score with the grade in biology from the secondary school diploma was shown. Its substitution with another grade from the diploma (for example with that in mathematics, having the highest correlation coefficient with the total score) would increase the sensitivity of the total score as a measure of applicants' knowledge and minimize the influence of errors upon the evaluation.
Our results suggested a real possibility to influence the optimal distribution of veterinary specialists throughout the territory of the country not only by a qualified training. The university could also assist in the management of the complex social process of distribution of specialists throughout the country using only the modelling of the social interest.
Key words: education, evaluation, statistics, veterinary medicine