Reconsideration of the diagnostic criteria required for PCV2 reproductive disease.

Porcine circovirus type 2 (PCV2) causes a variety of clinical conditions including PCV2-associated reproductive disease (PCV2-RD) characterized by late term abortions and mummifications. The generally accepted diagnostic triad includes the presence of reproductive disorders, the histopathological finding of myocarditis, and detection of moderate to high viral loads within the heart tissue. A new threshold of 109 PCV2 genome equivalents (GE)/g heart tissue is suggested to fulfil the third criterion using the diagnostic settings of quantitative real time PCR and in situ hybridization of 30 fetal heart tissues. The need to identify histopathological lesions in fetal heart tissue appears to be invalid or overestimated in confirming a diagnosis of PCV2-RD, at least at the individual fetus level. The highest viral loads (1012 GE/g tissue) were detected in autolyzed and mummified piglets and were identified as PCV2d, although concurrent detection of PCV2d + a and PCV2d + b also occurred.

Association between Pneumocystis spp. and co-infections with Bordetella bronchiseptica, Mycoplasma hyopneumoniae and Pasteurella multocida in Austrian pigs with pneumonia.

In this retrospective study, 218 pig lung tissue samples were analyzed to examine a possible association between Pneumocystis spp. using in situ hybridization, Bordetella bronchiseptica (B.b.) using immunohistochemistry (IHC), Mycoplasma hyopneumoniae (M.h.) by quantitative PCR, and Pasteurella multocida (P.m.; IHC). Compared to the bacterial agents (B.b., 5%; M.h., 30%; P.m., 23%), Pneumocystis occurred with a higher prevalence (51%). Co-infections with two or three pathogens were present in 28% of the examined cases. Those of Pneumocystis and M.h. were most commonly seen, followed by Pneumocystis and P.m. and M.h. and P.m. Histologically, interstitial pneumonia was found in both the Pneumocystis positive lungs and lungs with a mild M.h. infection. The B.b. and P.m. positive lungs were mainly associated with suppurative bronchopneumonia and severe M.h. cases with fibrinous or fibrino-haemorrhagic pneumonia. In suckling piglets, the number of samples positive for Pneumocystis predominated, whereas samples from fattening pigs were mainly positive for bacteria or Pneumocystis and bacteria.

[Field trial on the simultaneous vaccination against porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae]. / Feldstudie zur simultanen Vakzination gegen das porzine Circovirus Typ 2 und Mycoplasma hyopneumoniae.

OBJECTIVE: The objective of the present study was to investigate whether a combined or concurrent application of two vaccines against Mycoplasma hyopneumoniae (M. hyo.) and porcine circovirus type 2 (PCV2) in suckling piglets can be as effective as the single use of both products. MATERIAL AND METHODS: A total of 598 piglets were allocated to five groups. In the 1st and 3rd weeks of life the placebo Porcilis® Diluvac forte and the two vaccines Porcilis® M HYO ("M HYO") and Porcilis® PCV ("PCV") were administered according to the following scheme: group A: placebo/PCV; group B: M HYO/M HYO; group C: placebo/placebo; group D: M HYO/M HYO + PCV (combined single dose); group E: placebo/M HYO + PCV (different injection sites). Lung lesions due to M. hyo. infection were recorded at slaughter, and average daily weight gain, morbidity, mortality, serum PCV2 load and specific humoral immune responses were compared between the groups. Local and systemic side effects were recorded. RESULTS: Sporadic impairment of the herd health status due to piglet diarrhoea (n = 111) from the 1st to 3rd weeks of life were not associated with M. hyo. or PCV2. A tendency towards a higher average daily weight gain was found in vaccinated pigs compared to the control group. Slight differences between groups in terms of lung lesions, morbidity and mortality were not significant. M. hyo. and PCV2 antibody-titers were significantly higher in vaccinated than in non-vaccinated pigs. One pig from both group A (PCV2) and group C (placebo) displayed local reactions at the vaccination site. CONCLUSION AND CLINICAL RELEVANCE: A positive effect on animal health can be achieved by vaccination against M. hyo. and PCV2 in herds with suboptimal health status. A simultaneous vaccination either by a combined or concurrent application has no negative effect on health status. Simultaneous vaccination yielded the same positive effect on average daily weight gain as single vaccinations. Therefore, a simultaneous vaccination against M. hyo. and PCV2, which reduces workload and is beneficial for animal welfare, can be recommended.

Porcine ear necrosis syndrome: a preliminary investigation of putative infectious agents in piglets and mycotoxins in feed.

The aim of this study was to identify the causative factors of porcine ear necrosis syndrome (PENS) in 72 pigs, 5.5-10 weeks in age housed on nine farms. Biopsy samples of ear pinnae were collected from all piglets for bacteriology, histopathology and in situ hybridization for porcine circovirus type 2 (PCV2). At the same time, serum samples were taken for serological analysis and viral PCR, and feed was sampled for mycotoxin analysis. The initial lesion of PENS seemed to be a focal epidermal necrosis. Streptococci were isolated from 44 and staphylococci from 36 pinnae. PCV2 could not be detected by in situ hybridization or qPCR. Seven piglets were positive for porcine reproductive and respiratory syndrome virus, and one for Mycoplasma suis. One piglet had antibodies against Sarcoptes scabiei var. suis. No infectious agents were found in 15 samples. Positive virology and parasitology were often found alongside positive bacteriology. Deoxynivalenol, zearalenone and ergot alkaloids were detected in feed. The findings suggest that PENS is multifactorial in origin and that although infectious agents can be involved in the development of the syndrome they are not the exclusive triggering factor.