The examinations performed in herd A are summarized in Table 4. The first two episodes of sudden death problems in 3 day old piglets (December 2013 and January 2014) were not thought to be related with EMCV because no signs indicative for EMCV were observed. Instead E. coli was suspected as the causative pathogen. However, in January 2014 no virulence factors for E. coli (F4, F5, F6 or F41 adhesion factors; LT, STa and STb toxins) were found. An intoxication appeared to be unlikely due to the clustering of problems. Dead piglets did not appear to have been crushed by the sow and they were often heavier than the remaining pigs. The microclimate appeared to be good for the piglets. The first examination suggesting EMCV took place in June 2014 and was performed by the herd veterinarian. Upon necropsy of a 5 day old piglet, a very subtle lesion on the heart compatible with EMCV was observed (Fig. 2).  
Necropsies that followed were also suggestive to an EMCV infection except the one on August 12 probably because no typical piglets were available at that time. The hearts of two necropsied piglets were submitted to a real-time TaqMan PCR assay targeting a 80 bp segment in the 3D polymerase region. No conclusive diagnosis could be made as PCR results turned out negative. Pathognomonic EMCV lesions were not present or appeared to be very subtle.
In addition to these examinations, all individual sow reproduction data were analyzed in August 2014 whether parity, number of live born piglets, number of stillborn piglets, and number of mummies were associated with the problems. None of these factors turned out as a potential risk factor.
In herd B two main examinations took place, summarized in Table 5. Immediately EMCV was suspected in this case although other diseases such as edema and Glassers disease and streptococcal meningitis could cause sudden death in the nursery. However clinical nervous signs and slower progression of disease would be expected. A real time PCR was performed to demonstrate EMCV but similar as in herd A the result was negative. Because all PCR results were negative, the hypothesis rose that these farms were facing an uncommon variant of EMCV. The samples from farm A and B were submitted to two individual gel-based real time PCR assays targeting either a 903 bp region in the capsid coding region using primer CCR-L and CCR-R or a 268 bp region in the 3D polymerase gene using primers P1 and P2. PCR results turned out to be positive with the gel-based real time PCR. Sequencing of the 3D pol segment did not indicate the presence of mutation in the genetic sequence susceptible to alter the hybridization of the primers or the probe in the real-time PCR assay. It was further demonstrated that amplification with the real-time PCR primers occurred but detection with the Taqman probe failed. As a consequence, the real-time PCR test was adapted with replacement of the Taqman probe by SYBR  Green dye (Roche diagnostics, Belgium) in order to improve pathogen detection. 
Control of EMCV infections is mainly focused on preventing EMCV to enter the pig herd and to prevent transmission within the herd and hence internal and external biosecurity play a major role in controlling this disease.
Herd A was advised to pay more attention to cleaning and disinfection, especially the feeding troughs of the sows and the drinking troughs of the piglets. A longer stand-empty period of the compartments had to be practiced. As mentioned before, herd A produced according to a 4-week batch system and farrowing houses were continuously in use, making it rather impossible to implement this measure. Furthermore, the farmer was advised to reduce stress and excitation as much as possible e.g. limiting moving piglets from one sow to another, not performing teeth clipping and washing sows for the time being. The farmer refused to drop all preventive treatments of the piglets because he expected a lot of problems afterwards. Piglets were still being treated against coccidiosis, vaccinated against Mycoplasma hyopneumoniae, tails were docked and ear tags were placed. Feeding practices, light scheme and climate conditions were not altered. Pets such as cats and dogs were not allowed to enter the stables anymore. Because of insufficient quality of the water, water from the public supply was provided to the next group.
The farmer of this herd was advised to increase the overall biosecurity level of his herd. Examples of this advice were: providing boots and clothes for visitors, installing disinfection baths, following logical walking lines, color codes for material used per age group, removing cadavers as soon as possible, etc... Interventions inducing stress or excitation were reduced as much as possible. A longer stand-empty period after disinfection and cleaning of the rooms was practiced. Furthermore, a more stringent rodent control was implemented by a professional company. Possible access routes (windows, ventilation gaps in doors) for rodents were closed including the top of feeding troughs in the nursery. Similar as in herd A, pets were denied access to buildings.
After implementing all recommendations no EMCV outbreak has occurred until the time of submitting this paper. Only one piglet was suspected of EMCV by the farmer, but no diagnostics were performed. To avoid any risk, the herd was advised to utilize water from the public supply for next groups as well. After 3 months water was switched back to rainwater and ground water without negative consequences.
After the two suspicious cases, no more pigs with typical EMCV signs had died. It seemed the situation was normalized on this herd.