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27ВЕТЕРИНАРНЫЕ НАУКИ
PREVENTION AND CONTROL MEASURES AGAINST LISTERIOSIS OF SHEEP
1 2 3
Ashirali B. , Murzabayev K. , Kereyev A.
1Ashirali Balzhan - Graduate Student;
2Murzabayev Kenzhebek - Candidate of Veterinary Science;
3Kereyev Abzal - PhD of Science in Veterinary Medicine, DIRECTION: VETERINARY WEST KAZAKHSTAN AGRICULTURAL TECHNICAL UNIVERSITY NAMED AFTER ZHANGIR KHAN, URALSK, REPUBLIC OF KAZAKHSTAN
Abstract: listeriosis is a widespread disease of animals and humans which is registered in many countries of the world. The economic damage caused by listeriosis is determined by the high lethality of the disease, reduced productivity of animals, abortions, large funds spent on therapeutic and preventive and quarantine restrictive measures. Also Listeria are widespread in nature and are very resistant to environmental factors. In this regard, veterinary specialists are required to know the features of the disease, etiology, methods of diagnosis, and especially to prevent listeriosis to be able to apply methods of prevention and control.
Keywords: infectious diseases, listeriosis, prevention, control measures, sheep.
In the Republic of Kazakhstan and the CIS countries annually identified problem points on animal listeriosis, especially sheep. Economic damage is significant and consists of the mortality of animals, reducing their productivity, abortion, as well as the cost of therapeutic and preventive measures [1].
To date, the Listeria is widely distributed in animals and registered in 47 countries. The economic damage caused by listeriosis is determined by the high mortality rate from this disease, which reaches 47%, and in nervous forms of the disease can reach 98-100%, a decrease in the productivity of animals, abortions, large funds spent on therapeutic, preventive and quarantine restrictive measures [2]. In many scientific centers of the world conducted extensive research on listeriosis of animals and humans, the study of the biological properties of the pathogen. Epizootological and epidemiological significance of listeriosis is now generally recognized. It was found that Listeria are widespread in nature and very resistant to environmental factors [3].
To listeriosis susceptible sheep, goats, cattle, pigs, horses, rabbits, chickens, geese, ducks, turkeys. The disease was noted in fur animals (chinchillas, mink), as well as in trout in fish nurseries. In Kazakhstan, sheep are more often affected, they have the most significant morbidity with high mortality and mortality rates. Listeriosis affects animals of all ages, especially sensitive young and pregnant animals [4].
Currently, the genus Listeria includes 6 species: L. monocytogenes, L. innocua, L. ivanovii, L. welshimeri, L. seeligeri, L. grayi, and L. Monocytogenes are pathogenic for humans and animals, L. ivanovii is only for animals [5]. In sheep sheep are often infected by the pathogen - Listeriamonocytogenes, polymorphic, do not form spores and capsules aerobic, small (0,3-0,5 * 0,8-2mhkpoh) bacterium with rounded ends; there are also ovoid, coccoid forms of the pathogen. Listeria persist in the external environment for a long time, are able to reproduce in dead tissues and in silage at low temperature. The source of the causative agent of listeriosis is sick and ill animals that emit Listeria into the external environment with the expiration of the nasal cavity and genitals (with abortions), with an aborted fruit, feces, urine, milk (with mastitis), as well as healthy animals - Listeria carriers, which play an important role in the occurrence of outbreaks.
The great role of spoiled silage in the appearance of listeriosis is noted, especially in sheep. Listeria, getting with plants in the silo, can accumulate in it, especially if the pH of the silo is shifted to the alkaline side. The most intensive accumulation of Listeria occurs in the surface layers of the silo, which are exposed to low temperatures, which contributes to the reproduction of Listeria.
Listeriosis manifests itself sporadically, less often-in the form of epizootics. In sheep, the disease is seasonal and more often manifests itself in the winter-spring period. This is due to the influence of a number of factors, in particular, during this period, the mechanism of transmission of the pathogen is activated, rodents migrate in the autumn to livestock premises and feed stores.
In addition, non-specific resistance of animals to this time is reduced. In these months in the diet of animals often use the silage, which under certain conditions may be infected with Listeria. In spring and summer, when sheep are on pastures, their contacts with infected rodents are not so intense; solar radiation actively suppresses Listeria in the environment. Resistance of the sheep organism is also high, so the disease of animal listeriosis at this time, as a rule, does not occur. The incidence in most cases does not exceed 0.5 - 5 %, but sometimes can reach 20% or more. In the listeriosis of sheep, there are signs of damage to the Central nervous system: paresis of the lower jaw, ears, and lips, bulging eyes, uncoordinated movement, there is a crowding of the head back, drooling. In some animals, you can observe bouts of violence, severe nervous disorders, resembling rabies, however, without aggression. Sick animals die in a state of prostration within a few days from the appearance of signs of CNS damage. The genital form of the disease in sheep occurs with signs of abortion, detention of the placenta, endometritis, mastitis. The prognosis for this form of the disease is favorable. In lambs listeriosis occurs in the form of septicemia, in some cases.
Infection of animals with listeriosis in natural conditions occurs through the mucous membrane of the nasal and oral cavities, conjunctiva, digestive tract, damaged skin. The introduction of Listeria into the body can lead to the development of sepsis, the defeat of individual organs and systems, as well as to asymptomatic disease. The emergence of various forms of the disease depends on the virulence of the microbe, the infecting dose, the ways of infection, as well as the age of the animal, the physiological state (pregnancy), the nature of feeding and maintenance, the presence of concomitant diseases. The spread of Listeria in the body occurs neurogenic (perineural pathways), lymphogenic and hematogenous ways. In adult animals, the disease is sometimes asymptomatic, while animals remain carriers of Listeria for a long time. Long-term Listeria-carrier is due to the inability of macrophages to completely phagocyte the pathogen, which also contributes to the long (up to a year) life of macrophages.
The diagnosis is based on the analysis of epizootological data, clinical signs and bacteriological studies, taking into account the results of autopsy and serological studies. In the laboratory, send a fresh corpse or head (brain) and parenchymal organs; abortion - the fetus, its shell and the expiration of the genitals. The material is preserved with a 30 % aqueous solution of glycerin or frozen. Listeriosis should be differentiated from a number of diseases. Malignant catarrhal fever is characterized by high body temperature, keratitis, rhinitis and stomatitis. Brucellosis, campylobacteriosis and trichomoniasis are characterized mainly only by abortions, placenta detentions, orchitis and epididymis, while in listeriosis clinical manifestations are very diverse and often the first plan is the defeat of the Central nervous system. Aujeszky's disease is characterized by severe contagiousness, rapid spread, fever and respiratory damage in adult pigs. When colibacillosis (edema disease) affects only pigs, marked swelling in the head area. Coenurosis is differentiated on the basis of detection of coenurus in the brain, a longer course. Rabies is characterized by a characteristic clinical picture, aggressiveness, the presence of Taurus Babesh - Negri. When diagnosing listeriosis, it is necessary to remember about the possibility of mixed infection. The best effect gives a
safety (preventive) therapy animals conventionally advantaged (suspected infection) to prevent the spread of the disease. Most effective when listeriosis biomitsin, terramycin, tetracycline. For preventive purposes, biomycin is used at a dose of 20 mg, terramycin at a dose of 25 mg per 1 kg of live weight 1 to 2 times a day for 5 to 7 days. If necessary, the course of treatment is repeated after 5 to 6 days.
For therapeutic purposes, biomycin is used at a dose of 25 mg, terramycin at a dose of 30 mg per 1 kg of live weight 2 to 3 times a day until clinical recovery and a few days later to prevent relapses of the disease. Good therapeutic effect has ampicillin. At the same time, symptomatic treatment is carried out (cardiac drugs; means that improve the activity of the gastrointestinal tract; antimicrobial, astringent, etc.). In the process of listeriosis, agglutinins and complementary antibodies accumulate in the blood of animals. However listeriosny serum and extracted gamma-globulins possess neither preventive, nor curative properties. Since 1975, in the USSR used in poor listeriosis farms dry live vaccine from avirulent strain of ACE.
In order to prevent listeriosis acquire animals in farms that are safe for this disease, constantly monitor the quality of feed, are fighting rodents. Upon the occurrence of listeriosis conduct universal examination of the animals by measuring body temperature. Patients with signs of Central nervous system damage are directed to slaughter. Suspicious for a disease, isolate and treat. Space, where patients with listeriosis, the animals, cleaned and disinfected (hot 3% R-R sodium hydroxide, 5 % emulsion xylonite, 6 % emulsion of disinfection creoline, a 20% suspension spiegasti lime, chlorine solution with a content of not less than 2% of active chlorine). You can hold and spray disinfection of premises 20% aqueous solution of formaldehyde, formalin or formalin kilometrovoj-kremlinului mixture. The manure is disinfected biothermal. Destroy rodents in livestock rooms, warehouses and in the territory of farms. The head and the affected internal organs (liver, spleen, heart) with necrosis foci, intestines, bladder of the killed animals are disposed of. Carcass and unaffected internal organs boil pieces of no more than 2 kg within 2 h. Particular attention should be paid to the workers compliance with measures of personal prophylaxis in the slaughter and butchering.
The farm where the animal disease listeriosis, announce unfavorable. Prohibit input and output of animals, with the exception of withdrawal for slaughter; export of meat of slaughtered animals in the uncleared, with the exception of export to the meat processing plants for processing into cooked products; export of feed that have been in contact with sick animals listeriosis. The farm is declared safe in 2 months after the last clinically ill animal is isolated and the final mechanical cleaning and disinfection of the premises and the territory of the farms is carried out.
References
1. Infectious diseases of animals / B.F. Bessarabov, E.S. Voronin etc.; ed. M.: Koloss, 2007. 671 p.
2. KnizeA.V., BuzunA.D., SharmaR.K. epizootic situation on listeriosis In the countries of the world and Russia / / Proceedings Of the international Symposium "Listeriosis of the Millennium". Russian Academy of agricultural Sciences. VNIIVVIM. Holy Protection, 1999. P. 118-123.
3. Bakulov I.A., Kotlyarov V.M. The infection of T. I. epizootological and Epidemiological aspects of listeriosis. Journal. microbiol 1994; 5; 100-5.
4. BakulovI.A. Listeriosis of farm animals / I.A. Bakulov. M.: Kolos, 1967. 296 p.
5. Podounova L.G., Krivopalov N. With. etc. Microbiological rapid analysis and the possibility of its use in the practice of bacteriological laboratories and centres of the state. M: Snico., 1994. № 3. P. 16-17.
