Descriptive analyses of maternally-derived antibody levels against porcine circovirus 2 (PCV-2) in 3- and 21-day-old piglets from farms of four European countries using different vaccination protocols in sows.

BACKGROUND: Up to now, information on the levels of maternally-derived antibodies (MDA) against PCV-2 in suckling piglets born to sows vaccinated with different strategies is scarce in the literature. In the present observational study, the PCV-2-specific MDA titres from piglets from 109 farms (thirty 3-day-old and thirty 21-day-old piglets per farm) across four different European countries (France n = 30, Germany n = 27, Italy n = 22 and Spain n = 30) using different sow vaccination strategies (during gestation, as a gilt, as a piglet or never) were assessed. RESULTS: In all four countries, mean log PCV-2 MDA titres were higher in 3-day-old piglets than in the 3-week-old ones, being significant in most of all the comparisons performed. Within each country, the highest PCV-2-specific MDA titres were observed in the 3-day-old piglets born to sows vaccinated during gestation. Indeed, in the four countries, more than 60% of this subpopulation (3-day-old piglets from sows vaccinated during pregnancy) had the highest log PCV-2 titres detectable with the ELISA technique used in this study. The lowest MDA titres were more variable. Whereas in France and Germany the lowest titres corresponded to 21-day-old piglets born from sows vaccinated as a piglet, in Italy, they corresponded to 21-day-old piglets derived from sows vaccinated as a gilt and in Spain to 21-day-old piglets born from non-vaccinated sows. In this study, PCV-2-specific MDA titres at 3 and 21 days of age were not affected by sow parity. CONCLUSIONS: Data obtained could be considered as a European global overview of PCV-2-specific MDA titres present in the pre-vaccinated piglet populations in different European countries, with titres tending to be higher in younger piglets, but with values variable among countries and sow vaccination strategies.

An Outbreak of Porcine Reproductive and Respiratory Syndrome Virus in Switzerland Following Import of Boar Semen.

An outbreak of porcine reproductive and respiratory syndrome virus (PRRSV) occurred in November 2012 in Switzerland (CH), traditionally PRRSV-free. It was detected after a German boar stud informed a semen importer about the detection of PRRSV during routine monitoring. Tracing of semen deliveries revealed 26 Swiss sow herds that had used semen from this stud after its last negative routine monitoring and 62 further contact herds. All herds were put under movement restrictions and examined serologically and virologically. As a first measure, 59 sows from five herds that had previously been inseminated with suspicious semen were slaughtered and tested immediately. Investigations in the stud resulted in 8 positive boars with recent semen deliveries to CH (Seven with antibodies and virus, one with antibodies only). In one boar out of six tested, virus was detected in semen. Of the 59 slaughtered sows, five from three herds were virus-positive. In one herd, the virus had spread, and all pigs were slaughtered or non-marketable animals euthanized. In the remaining herds, no further infections were detected. After confirmatory testings in all herds 3 weeks after the first examination gave negative results, restrictions were lifted in January 2013, and Switzerland regained its PRRSV-free status. The events demonstrate that import of semen from non-PRRS-free countries--even from negative studs--poses a risk, because monitoring protocols in boar studs are often insufficient to timely detect an infection, and infections of sows/herds occur even with low numbers of semen doses. The outbreak was eradicated successfully mainly due to the high disease awareness of the importer and because immediate actions were taken before clinical or laboratory diagnosis of a single case in the country was made. To minimize the risk of an introduction of PRRSV in the future, stricter import guidelines for boar semen have been implemented.

Histopathologic lesions in conventional pigs experimentally infected with Haemophilus parasuis serovar 5.

OBJECTIVE: In the present study various tissues of pigs were investigated for the presence of histopathologic lesions after an experimental infection with Haemophilus (H.) parasuis serovar 5. MATERIAL AND METHODS: Conventional pigs (n = 36) were divided into a control group B (n = 9) and a challenge group A (n = 27), which was infected intratracheally. Pigs that did not die prior to study termination were euthanized on day 14 post inoculation. Postmortem samples of the lung, heart, liver, kidney, spleen, left tarsal joint capsule and brain were collected. RESULTS: All but one pig with detectable histopathologic lesions (n = 11) showed typical macroscopic changes. Histopathologic examination of all tissue samples identified pyelitis (n = 10), synovitis (n = 7) and meningitis (n = 7) and all those animals were euthanized prior to study termination. No histopathologic lesions were found in pigs of the control group. The correlations between pyelitis and meningitis, pyelitis and synovitis and synovitis and meningitis were significant (p < 0.001). No significant correlation could be observed between the histopathologic and the clinical examination of the joints. The investigation of samples from the joints by PCR was not significantly correlated with the observed synovitis. The clinical observation of neurologic signs was significantly correlated with meningitis (p = 0.03). A significant correlation (p < 0.001) could be detected between meningitis and the detection of H. parasuis by PCR in brain samples. CONCLUSIONS: H. parasuis constantly causes clinical signs and pathologic lesions as soon as it infects the brain while it can infect the joints without causing histopathologic lesions. Pigs with histopathologic lesions do not always show typical clinical signs. Only few studies described the finding of kidney lesions in pigs with Glässer's disease and this is the first study to describe a pyelitis in pigs experimentally infected with H. parasuis. The observed pyelitis mainly occurred in acute cases.

Detection of a new cluster of porcine circovirus type 2b strains in domestic pigs in Germany.

PCV2 can be divided into three different genotypes: PCV2a, PCV2b and PCV2c. Since 2004/2005 PCV2b has become the predominant genotype in the domestic pig population worldwide. In the years 2010 and 2012 PCV2b mutant strains (mPCV2), classified as PCV2b-1C strains, were detected in porcine circovirus diseases (PCVD) affected pigs in China and the United States, respectively. Within one year (April 2013-April 2014) newly emerging mPCV2 strains were isolated in seven German pig farms routinely vaccinating against PCV2. Histopathological, clinical and molecular biological findings including in-situ hybridization (ISH) and real-time PCR indicate PCVD in the affected animals. Characterized isolates from five farms were closely related to the PCV2b-1C reference strain BDH (GenBank no. HM038017), whereas strains from two other farms were only 99.1% and 99.0% identical (based on the nucleotide sequence of the complete genome) to mPCV2 strain BDH, respectively.

[Serological course investigations of Haemophilus parasuis and Mycoplasma hyorhinis in three pig farms]. / Serologische Verlaufsuntersuchungen auf Haemophilus parasuis und Mycoplasma hyorhinis in drei schweine-haltenden Betrieben.

The aim of the study was to investigate the infection dynamic of Haemophilus (H.)parasuis and Mycoplasma (M.) hyorhinis in 3 farms. A total of 61 piglets were clinically investigated at 1., 3., 5., 7., 9., 11., 14., 18. and 22. weeks of life and a blood sample was taken from each piglet as well as from the sows. The serum samples were tested using ELISA for antibodies against H. parasuis and M. hyorhinis. Clinical signs indicating polyserositis were seen in farm 1 and 3. For both pathogens, a decline of the maternal antibodies could be detected up to the 5th or 7th week of life. The duration of persistence depended on the level of the maternal antibodies. In farm 1, all animals were tested positive for antibodies against H. parasuis during the fattening period. In farm 3, several sows were tested positive in the M. hyorhinis ELISA, therefore, positive results in sows can indicate a higher infection dynamic during the fattening period. For H. parasuis as well as for M. hyorhinis a significant correlation between the level of the antibodies in the sows and their piglets could be seen.

[Evaluation of the efficacy of a combination therapy of an antibiotic and a NSAID following an experimental Haemophilus parasuis infection in nursery piglets]. / Wirksamkeitsbeurteilung einer Kombinationstherapie aus Antibiose und NSAID nach experimenteller Haemophilus-parasuis-Infektion bei Absetzferkeln.

OBJECTIVE: The aim of the present study was to evaluate the combination therapy of an antibiotic (enrofloxacine-arginine, Baytril® RSi) and a non-steroidal anti-inflammatory drug (NSAID, ketoprofen, Dinalgen® 60 mg/ml) against a Haemophilus parasuis (HPS) infection in nursery piglets. MATERIAL AND METHODS: Forty-eight 3-week-old pigs were divided into four groups (group 1: non-infected controls; group 2: HPS infection; group 3: HPS infection/Baytril® RSi; group 4: HPS infection/Baytril® RSi/Dinalgen®) and housed within the isolation facility. After an acclimatization period of 10 days, the piglets in groups 2-4 were intratracheally infected with 1 x 107 colony forming units (CFU) HPS serovar 5, whereas animals of group 1 received physiological saline. Total clinical scores and joint scores were calculated daily after clinical examination. Seven days after the infection, piglets were humanely euthanized. At necropsy, pathological findings on serosal surfaces were scored according to severity and extension. RESULTS: Group 1 had the lowest clinical and pathological scores, followed by groups 4, 3 and 2. Piglets treated with the combination of an antibiotic and an NSAID showed the lowest body temperatures (significant). The average daily weight gain (ADWG) was not significantly different between the groups, but piglets of group 4 tended to reach a higher mean ADWG (340.5 g/d) than animals of the non-infected group 1 (323.8 g/d), the Baytril® RSi-treated group 3 (278.0 g/d) and the positive control group 2 (247.0 g/d). Piglets of the positive control group (group 2) achieved the highest values in the clinical, joint and serositis scores. CONCLUSION: The study demonstrated that a simultaneous treatment with enrofloxacine-arginine (Baytril® RSi) and ketoprofen had a superior therapeutic effect compared to a single antibiotic treatment with Baytril® RSi in nursery piglets experimentally infected with HPS.

[Effect of a synthetic GnRF vaccine (Improvac®) on daily weight gain and carcass quality of boars. A field trial in Bavaria]. / Einfluss einer GnRH-Vakzine (Improvac®) auf Gewichtszunahmen und Schlachtkörperqualität von Ebern. Ein Feldversuch in Bayern.

OBJECTIVE: The effects of vaccination against gonadotropin releasing factor (GnRF) with Improvac® (Pfizer Animal Health) were compared with surgical castration in fattening pigs. MATERIAL AND METHODS: A total of 205 pigs were surgically castrated (group K) and 191 were vaccinated twice (group V) using the boar taint vaccine (Improvac®; 2ml s.c.). The first dose was administered atthe age of 12 weeks when the animals were moved into the fattening unit and the second dose in week 18, 4-6 weeks before the planned slaughter date. Live weights were recorded in weeks 1, 4, 12, 18, and 22. In weeks 18 and 20, length and width of the testicles of 171 animals of group V were measured. After slaughtering cold carcass weight, back fat depth, muscle thickness, percent lean meat, and fat and muscle areas of the carcasses were determined. A piece of the neck muscle from each pig was used to conduct a cooking and melting sensory test. RESULTS: While no significant weight difference was evident in week 22 (K=89.4kg; V=88.6kg), cold carcass weight, and back fat and muscle thickness were lower for vaccinates. Vaccinates had higher average daily weight gains (ADW) after the second injection from week 18 up to the cut-off weighing in week 22 (V=1121g; K=1007g; p<0.001) in contrast to average daily weight gains between weeks 12 and 18 (K=740g; V=668g; p<0.001). After the second injection, testicle size of vaccinated pigs decreased significantly. All animals were negative for boar taint by both cooking and melting tests. CONCLUSION: Boars vaccinated against boar taint had lower ADW before the second vaccination, but compensated the weight difference after complete vaccination. The significant reduction in the testicle size after the second injection indicates a vaccination success. After vaccination no boar taint was detected in carcasses. CLINICAL RELEVANCE: Vaccination as well as surgical castration reliably prevents the incidence of boar taint. The late rise in daily gain can be beneficial if management is aligned.

Associations between pathogens in healthy pigs and pigs with pneumonia.

The aim of this study was to evaluate the associations between different pathogens in the development of pneumonia and bronchopneumonia in pigs. Samples of bronchoalveolar lavage fluid from 100 pigs showing no clinical signs and 239 pigs with clinical signs of respiratory disease were examined for Mycoplasma hyopneumoniae, Mycoplasma hyorhinis, US-type porcine respiratory and reproductive syndrome virus (PRRSV), EU-type PRRSV, porcine circovirus type 2 (pcv-2), influenza virus type A, alpha-haemolytic Streptococcus species, beta-haemolytic Streptococcus species, Pasteurella multocida, Bordetella bronchiseptica, Haemophilus parasuis and Actinobacillus pleuropneumoniae. These potential pathogens were detected more frequently in the pigs with respiratory problems than in the pigs with no clinical signs. pcv-2 and alpha-haemolytic streptococci were the pathogens most frequently detected; A pleuropneumoniae was isolated in only two cases. There were more often associations between the organisms in the pigs with clinical signs than in the healthy pigs. In particular, alpha-haemolytic streptococci and M hyopneumoniae were both associated with the presence of M hyorhinis, EU-type PRRSV, P multocida and B bronchiseptica, and alpha-haemolytic streptococci also occurred more often in pigs that were already infected with other pathogens. P multocida and B bronchiseptica were both significantly associated with M hyopneumoniae, alpha-haemolytic streptococci, EU-type PRRSV and US-type PRRSV.

[A field trial for early vaccination against Gässer's disease using Porcilis Glässer]. / Frühe Vakzinierung gegen die Glässersche Krankheit mit Porcilis Glässer in einem Feldversuch.

The goal of this study was to examine the use of an early vaccine for Haemophilus parasuis in three and five week old piglets. In the first field trial, 144 female piglets were divided into four groups. The groups consisted of animals showing no clinical signs of the disease (clinically normal) and a second group displaying clinical signs of the disease (clinically suspect). Half of the animals belonging to both clinical groups were vaccinated. In a second field trial, 240 female piglets, which were clinically normal at the time of housing and originating from the same farm were divided into two groups. Swine from one group were vaccinated, and both groups were regularly weighed and clinically examined until the end of the growing-finishing phase. Vaccinated animals from the first field trial which were clinically weighed on average 0.353 kg more than animals from the nonvaccinated control group at 11th weeks of age. Piglets of the vaccinated clinically suspected group which were 13 weeks of age weighed on average 1.41 kg more than the piglets from the nonvaccinated group. The average clinical scores for both vaccinated groups were lower than those from the nonvaccinated groups. The results from the second field trial showed that the average weight of the vaccinated group was higher by 3.1 kg than those of the control group.Also, a significant difference in weight gain was found beginning in the thirteenth week of age. The percentage of altered animals or animals unfit for growing-finishing was 8.3% in the nonvaccinated group at the end of the rearing phase. In comparison, this percentage was 3.8% in the vaccinated group.

[Changes in the concentration of noradrenaline and adrenaline before and after castration of piglets with and without isoflurane anesthesia]. / Verlauf der Noradrenalin- und Adrenalinkonzentrationen vor und nach der Kastration von Saugferkeln mit und ohne Isofluran-Narkose.

Since the amendment of the animal welfare law in Germany in April 2006, castration of piglets without anesthesia is only allowed in the first seven days of life. However, neonates are capable of feeling pain and react more sensitive to pain than adults. Accordingly we expect that castration without anesthesia will be unaccepted in Germany in the future as castration without anesthesia will be forbidden in Switzerland from 2009 on. Denmark and The Netherlands strive for an embargo of the castration without anesthesia and Norway is already asking for an elimination of pain during castration. In Switzerland castration under isoflurane-anesthesia is considered to be a good alternative for the castration without anesthesia. Whether isoflurane-anesthesia is able to reduce stress caused by castration adequately or anesthesia, especially anesthetization that often provokes defensive reaction, is stress for the animal itself was tested in the following investigation. To get an objective statement about the stress of the animals, concentrations of epinephrine and norepinephrine were detected before and immediately after castration/fixation with or without anesthesia. Five day old, healthy animals were divided into four groups. Animals of group A (n = 10) were only fixed without anesthesia, animals of group B (n = 10) were fixed and castrated without anesthesia. In group C (n = 10) the animals were only fixed under anesthesia and the animals of group D (n = 11) were fixed and castrated under anesthesia. Norepinephrine-concentrations and epinephrine-concentrations did rise significantly in all piglets handled without anesthesia (group A and B) independently if castrated or only handled. The values of these animals were significantly higher than the values of the anesthetized animals after fixation/castration (group C and D). In contrast the norepinephrine-concentrations and the epinephrine-concentrations of all anesthetized animals (group C and D) were significantly lower after castration than the concentrations before castration. The catecholamine peak did not differ significantly between the groups of anesthetized animals. The significant increase of the catecholamines of the non-anesthetized animals can be explained by the stress caused by fixation and/or castration without anesthesia. Because of the anesthesia the catecholamine-concentration was reduced considerably during the fixation and/or castration. The results show that fixation and/or castration under anesthesia causes no stress for the piglets.

[Detection of Haemophilus parasuis and Mycoplasma hyorhinis in swine and association of those pathogens with clinical and pathological-anatomic findings]. / Nachweis von Haemophilus parasuis und Mycoplasma hyorhinis bei Schweinen sowie Assoziation dieser Erreger mit klinischen und pathologisch-anatomischen Befunden.

In routine diagnostic it is difficult to detect a Haemophilus parasuis infection causing a polyserositis. In the presented study, a detection method by means of PCR, from collective swabs of the serosal surfaces from animals, with and without fibrinous serositis, was investigated. A significant association was detected between post mortal findings of fibrinous serositis and molecular biological detection of Haemophilus parasuis and Mycoplasma hyorhinis. However, no significant association existed between cultural detection of Haemophilus parasuis in bronchoalveolar lavage fluid and pathological-anatomical ascertainable fibrinous serositis. A significant association between Haemophilus parasuis and Mycoplasma hyorhinis could be determined in the animals that were included in this study.