Salmonella infections in swine herds--epidemiology and importance for human diseases]

Based on pertinent literature and research work performed by the authors, a report is presented on the presence of salmonellas in swine herds and the importance of these organisms as agents of disease in swine and source of infection for human salmonellosis. The share among human cases of salmonellosis which are caused by salmonellas originating from swine is estimated at ca. 20%. It has to be assumed that a very large proportion of swine herds is contaminated by Salmonella. Salmonellas may be introduced through infected pigs (parent animals, pigs from other herds added to the herd) or carriers among other animal species (e.g. rodent pests, birds) as well as by feeding stuffs with primary or secondary contamination. So far, the individual importance of the various routes cannot be reliably assessed. It appears that the level of Salmonella prevalence within a herd essentially depends on the hygienic conditions, the mode of keeping and the management of the animals. Serological examinations of meat juice permit conclusions as to the level of Salmonella contamination in slaughtered pigs. The results can thus be used for programmes to reduce the introduction of salmonellas into the food chain.     

Eradication of Mycoplasma hyopneumoniae from infected swine herds joining the LSO 2000 health class

The study was conducted in order to determine if eradication of swine enzootic pneumoniae (SEP) had succeeded with different variants of partial depopulation during the eradication programme on swine farrowing farms joining a health class, LSO 2000. The farms in the health class need to be free from swine enzootic pneumoniae, swine dysentery, sarcoptic mange and atrophic rhinitis. Twenty-one eradication attempts for M. hyopneumoniae were carried out using different variants based on separating adult animals for 2 weeks from infected young pigs which were not returned to the herd. The infected young pigs were kept in the same building (variant 1) in 4 herds and on the same compound (variant 2) as disease-free pigs in 12 herds. The infected young pigs were finally all sold. In 5 herds only adult animals were present during the eradication (variant 3). The eradication attempt succeeded in 81% and failed or remained uncertain in 19% of the herds. The result was confirmed with 1) frequent clinical follow-up of the health status in the herds (both the farrowing and the finishing units) joining the LSO 2000 health class 2) milk and/or blood serology. Possible causes of the failure of the eradication attempt were described: a short distance between infected and uninfected animals, the time period between diagnosis of SEP and initiation of the programme, the age of the youngest animal kept on the farm, the period of time when animals with different status were reared close to each other, the medications used, the cleaning of the facilities during the programme and the season. Further, a good cooperation between the farmer, the local veterinarian and the animal health service of the slaughterhouse was an essential part of the initiation and the follow-up of the programme. The secondary aim of the study was to collect information about the expenses during the programme. Only 57% of the farmers gave some estimates for the expenses on their farms. For variants 1, 2 and 3 the expenses were 879, 1110 and 1274 FIM per sow (1 USD = 5.5 FIM), respectively (p > 0.1).     

Uterine leiomyomas in two Vietnamese pot-bellied pigs (Sus scrofa)

Two Vietnamese pot-bellied pigs (Sus scrofa) were euthanatized after they developed abdominal distension. Necropsy of both pigs revealed large myometrial neoplasms and cystic endometrial hyperplasia. Multiple discrete smaller myometrial neoplasms were also observed in one pig; however, distant metastases were not observed in either animal. The tumors were diagnosed as leiomyomas on the basis of histologic examination and immunohistochemistry. This is the first detailed report of uterine leiomyomas in swine, and it is suggested that this diagnosis may become more common as more aging pigs are examined.     

Emergency care for potbellied pigs.

Because of the limited number of veterinarians treating potbellied pigs, many pet pigs do not receive proper preventative health care. The potbellied pig's continued popularity among urban dwellers ensures that veterinarians who treat small and exotic animals will be contacted by owners of pet pigs with real or perceived emergencies. Regardless of their knowledge of swine, the information contained in this article should enable any veterinarian to provide basic emergency care for pet pigs.     

Structures and possibilities of herd management on the example of respiratory enzootic infection of calves

With the keeping of cattle in bigger herds problems arise, which require a modified veterinary approach. In stead of and in addition to the treatment of individual animals improvement of hygiene, intensification of prophylaxis, fast recognition (herd diagnostics) and interregional comparability have to be established. Beside the conventional field veterinarian, who is consulted on request primarily for the treatment of single animals, specialists in team practices as an alternative, permanently employed veterinarians or firm contracts with a health service up to integrated herd control are thinkable. The clarification and control of infectious diseases of the respiratory tract in cattle operations require an exact analysis of the environmental conditions and the identification of etiologic agents. Special attention has to be drawn to the evaluation of the barn climate and the respective taking of samples concerning the actual disease situation.     

Biosecurity and minimal disease herds.

The minimal disease concept is a way of raising pigs so that some specific diseases are absent. Many bacteria and viruses can be transferred by pigs, air, or mechanical contact. To avoid contamination, the herd location should take into consideration disease transmission possibilities. Herd health status and source herd health status should be continuously monitored. To maintain herd health status, specific rules need to be followed for herd construction and establishment, compound perimeter, people movement, down time, animal transportation, feed use and delivery, vehicle movement, material, dead animal disposition, and rodent control. All new incoming animals should go through quarantine, and in some herds, safer methods such as AI, embryo transfer, MEW, or hysterectomy and fostering need to be used.     

Computer simulation model of swine production systems: III. A dynamic herd simulation model including reproduction

A dynamic herd simulation model for a swine production unit has been developed. The model is discrete and stochastic and the appropriate random distributions have been defined from the literature or empirically estimated. Theoretical concepts and relationships presented previously are used to simulate growth and the overall life cycle of individual animals. Simulated animals are young pigs (from birth to slaughter age), gilts, and sows. Animal events are farrowing, weaning, mating, end-nursery (transfer from nursery to the growing-finishing facility), and slaughter and are processed individually using a next-event scheduling orientation package. Animals within the herd are culled for different health and reproductive reasons. Genetic parameters, diet composition, and herd management are input variables chosen by the user. The effects of nutrition, genetics, season, and other factors on several reproductive parameters are considered. Model evaluation is performed by studying the output of the model under specified herd situations. The herd model adequately simulates animal flow and dynamics of the herd.     

Epidemiological investigation of swine tuberculosis in Arizona.

Swine tuberculosis occurred in thirteen herds of swine in Arizona. Mycobacterium avium serotypes 1, 2, 4, 5 and 8 were isolated from tissues of affected animals. These serotypes are responsible for approximately 85% of the mycobacterial infections found in swine in the United States. Based on tuberculin skin test responses and examinations of tissues collected at slaughter, the source of infection in at least one of these herds, Herd A, was found to be infected sawdust and wood shavings used as bedding. This finding concurs with the reports of others. Tuberculin skin tests performed on slaughter pigs in Herd A showed a 97.1% correlation between the number of pigs responding to tuberculin and the number found to have tuberculous lesions at slaughter. No correlation of skin test response and presence of lesions was possible for individual pigs, but these results imply that the test may have value when used to determine prevalence of the disease in a herd of pigs.     

Preventive health care for pet potbellied pigs.

Many small and exotic animal practitioners decline to see potbellied pigs, possibly because of their challenging behavior and the perception that in order to treat them, one must be very knowledgeable about swine medicine. With some basic information about their unique behavior and their preventive health care needs, however, seeing potbellied pigs in practice is easy and provides a much-needed service in many communities. The behavior of the pig, recommended methods of restraint, physical examination, vaccinations, and parasite control are all discussed.     

Veterinary dental care: effective, efficient, and patient/client focused

The treatment of dental problems in animals and humans requires a different approach. While a basic knowledge of medicine is sufficient for dentists, a degree in veterinary medicine is a prerequisite for performing dental procedures in animals. Concepts such as oral-health veterinarian and dental care technician will be part of animal dental care in the future. When deciding on the plan of treatment, veterinarians should pay attention to the symptomatology, oral examination, and pain response. A number of treatments that are self-evident in human dentistry are often not recommended in veterinary medicine. Dental treatments for companion animals should be characterized by minimal interventions with maximum results: effective, efficient, and most of all patient/client focused.     

Results of a survey of owners of miniature swine to characterize husbandry practices affecting risks of foreign animal disease

OBJECTIVE: To characterize husbandry practices that could affect the risks of foreign animal disease in miniature swine. DESIGN: Survey study. STUDY POPULATION: 106 owners of miniature swine. PROCEDURES: An online survey of owners of miniature swine was conducted to obtain information about miniature pig and owner demographics; pig husbandry; movements of pigs; and pig contacts with humans, other miniature swine, and livestock. RESULTS: 12 states, 106 premises, and 317 miniature swine were represented in the survey. More than a third (35%) of miniature swine owners also owned other livestock species. Regular contact with livestock species at other premises was reported by 13% of owners. More than a third of owners visited shows or fairs (39%) and club or association events (37%) where miniature swine were present. More than 40% of owners fed food waste to miniature swine. Approximately half (48%) of the veterinarians providing health care for miniature swine were in mixed-animal practice. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study indicated that miniature swine kept as pets can be exposed, directly and indirectly, to feed and other livestock, potentially introducing, establishing, or spreading a foreign animal disease such as foot-and-mouth disease. In addition, the veterinary services and carcass disposal methods used by miniature swine owners may reduce the likelihood of sick or dead pigs undergoing ante- or postmortem examination by a veterinarian.     

Natural infections of pigs with bovine viral diarrhoea virus associated with signs resembling swine fever

Between 1976 and 1985 while using immunofluorescence in the laboratory diagnosis of swine fever (SF), 13 incidents of bovine viral diarrhoea virus (BVDV) infection were detected in the Netherlands. Ultimate differentiation between swine fever virus (SFV) and BVDV was based on herd evidence supported by comparative antibody studies on sera from pigs inoculated with the isolate and from contact pigs in the herd of origin, using reference strains of SFV and BVDV. Recently differentiation of SFV and BVDV has been facilitated by typing the isolates with monoclonal antibodies. Signs suspicious of SF were observed in pigs two to 16 weeks old and were always confined to animals of one litter. In most cases the affected litter died out gradually although once an animal recovered. Stillbirth and neonatal death as well as the late onset of disease and its limitation to a single litter in a herd suggested a congenital route of infection. Although transplacental infection of BVDV in pigs has been reported before, these cases are believed to be the first in which natural BVDV infections could be associated with clinical signs and pathological lesions indistinguishable from those observed in chronic SF.     

The legal aspects of pre-purchase examinations.

This article should be of interest to every veterinarian who performs pre-purchase examinations. Important definitions are included that describe the legal relationship between the buyer, seller, and veterinarian. The author recommends that all examination agreements should be made in writing, signed by the buyer and seller, and include factual representations with respect to the animal to be examined. Copies of sample agreements are included in the Appendix.     

Molecular detection of bovine and porcine Torque teno virus in plasma and feces

Torque teno virus (TTV) is frequently detected in humans, livestock and some companion animals. Very little is known about presence of TTV in Canadian livestock and the goal of this study was to evaluate the presence of TTV in swine and cattle using molecular tools. TTV DNA was detected and confirmed by sequencing in the plasma of 90.5% and in the feces of 60.3% of the animals tested in a single swine herd as well as 80.9% and 1.1% in the plasma of individuals from general Quebec swine and cattle populations, respectively. The impact of the TTV presence in livestock population for the agri-food chain should be further investigated.     

Veterinary dairy herd health management in Europe: constraints and perspectives

The nature of veterinary work in dairy health management in Europe has changed over the past years and will change even more dramatically in the near future. The consumers and the media show increasing concern about animal welfare, safety of products of animal origin and traceability of animal products. Farmers in Europe have to produce under strict, often expensive and laborious regulations, while still commercially competing with farmers outside the EU and not subject to the same rules. Veterinarians should adapt their knowledge and skills to the new challenges and developments of the dairy sector. Dairy farmers nowadays ask for support in areas that go beyond clinical activities: environmental protection, welfare, nutrition, grassland management, economics and business management. Bovine practitioners should be able to advise in many different areas and subjects--that is the challenge to our profession. Veterinary education with regards to cattle health management should start with individual animal clinical work, which constitutes the basis of herd health advisory programmes. The bovine practitioner should then look beyond that and regard the herd as the unit. Each diseased cow or group of cows should be detected early enough to avoid financial losses or such losses should be prevented altogether by detecting and managing risk factors contributing to disease occurrence. Herd health and production management programmes represent the first level to optimise dairy farm performance. Expansions to that should further be considered, comprising both animal health and welfare issues, as well as food safety and public health issues. The latter could be addressed by quality risk management programmes following the HACCP-principles. Cattle veterinarians should follow recent developments and invest in new skills and knowledge in order to maintain their usefulness to the modern dairy farmer. Finally we are convinced that the cattle practitioner should evolve into this direction, otherwise the veterinarian as we know him will miss the train in the next years.     

Animal studies of potential chronic lung disease of workers in swine confinement buildings

The pathologic changes in laboratory animals housed in a swine confinement building were studied to predict potential chronic health effects on persons working in these buildings. Rabbits and guinea pigs were maintained for 12 months either in a confined nursery-grower unit (test animals) or in conventional laboratory animal housing (controls). Necropsies and histopathologic examinations were performed on animals that died prematurely or were killed at termination of the study. Blood serum from the animals was examined for antibodies to extracts from swine confinement house dust. The confinement atmosphere was monitored for environmental pollutants. Concentrations of gases and dust in the air of the confinement building were comparable to those found in a typical swine confinement building. Pulmonic lesions seen in the test rabbits and guinea pigs included diffuse interstitial histiocytic pneumonia. Tracheal and nasal turbinate lesions included epithelial hyperplasia and metaplasia, with submucosal infiltration of plasma cells and heterophils. Blood from the test animals contained serum precipitins to dust extract from confinement houses. The presence of precipitins combined with the microscopic appearance of the lungs indicated that an immunologic process, such as hypersensitivity pneumonitis, may be used to explain the basis of the observed lung lesions. The tracheal and turbinate lesions are best explained as a reaction to a chronic low-grade irritation.     

Model of an information system for veterinary fertility monitoring as part of an integrated herd management system

The requirements of the veterinarian's work are changing by reason of an increasing intensity of dairy industry. The model of an information system for monitoring and managing dairy herd health and management system is described. General and special requirements are illustrated. The program requires urgent development for the use of veterinarians and herd owners, including the provision of a data communication link to a veterinary-agricultural information system. The system should integrate the veterinarians into the animal production in order to improve herd health and to secure the veterinarian's role in, and facilitate the development of novel scientific approaches to, dairy herd health and management.     

Comparison of common fecal flotation techniques for the recovery of parasite eggs and oocysts

A variety of procedures are available to detect parasite eggs or oocysts in feces. This study compared the efficacy of simple flotation, a commercial assay, and various centrifugation techniques and three common flotation solutions. Results indicate that centrifugation consistently recovered more eggs than other methods. Proper technique is critical, including ensuring that the specific gravity of the flotation solution is correct and allowing the sample to stand for a sufficient amount of time before examining the coverslip. Because of the zoonotic health risks of many companion animal parasites, veterinarian and their staff should better utilize fecal examinations in their routine diagnostic plan.     

Urethroscopy and laser lithotripsy for the diagnosis and treatment of obstructive urolithiasis in goats and pot-bellied pigs

OBJECTIVE: To explore the use of urethral endoscopy and laser lithotripsy in the diagnosis and management of urolithiasis in goats and pot-bellied pigs. DESIGN: Prospective clinical study. ANIMALS: 16 male goats and 6 male pot-bellied pigs with dysuria. PROCEDURE: Abdominal ultrasonography and urethral endoscopy were performed on all 22 animals. Endoscopic-guided holmium:yttrium-aluminum-garnet laser lithotripsy was performed in 3 goats and 2 pot-bellied pigs. RESULTS: Urolithiasis was identified in 15 goats and 5 pot-bellied pigs. Primary urinary bladder paralysis and cystitis were identified in the remaining pot-bellied pig and goat. Mean bladder diameters of obstructed small- and large-breed goats were 7 and 9.5 cm, respectively. The mean bladder diameter of obstructed pot-bellied pigs was 9.5 cm. Five of 20 animals with obstructive urolithiasis had severe urethral necrosis or stricture formation at the time of urethroscopy. All of these animals were euthanatized within 6 months because of persistent dysuria. When used, laser lithotripsy successfully fractured the distally located obstructing stones in the 3 goats and 2 pot-bellied pigs. CONCLUSIONS AND CLINICAL RELEVANCE: Urethral endoscopy is useful for evaluating urethral patency in goats and pot-bellied pigs. Examination of the urethral mucosa following relief of urethral obstructions aids in the assessment of the long-term prognosis for urethral stricture. Urethral endoscopy also expands the therapeutic options for management of urolithiasis by providing a route for conducting laser lithotripsy. Laser lithotripsy proved to be safe and effective for clearing distally located calculi refractory to removal by traditional urethral flushing. Lithotripsy application is restricted to calculi lodged in the urethra.     

发达国家兽医协会的构成与职能

兽医协会早已有之,界定各国兽医协会历史比较困难。兽医协会一般均从兽医学会分立或隶属于兽医学会。兽医协会以会员利益为主体,服务于兽医行业,保护动物福利和健康。协会多由委员会及下属理事会构成。理事会是协会运作的主体,分设各职能分会、部门或机构。协会会员多需要经过正式的学术教育,且通过国家或地方兽医资格考试,有些国家还要求会员是注册兽医。兽医资格考试分为理论考试和临床技能考试。多数国家只需要通过理论考试,有些国家还需要通过临床技能考试。欧美国家还设有专科考试。