Articles - Pig health

Pigs can act as a source of new influenza strains with zoonotic potential, but the increase of the genetic diversity of the swine influenza viruses is largely due to the introduction of influenza strains of human origin. Therefore, it is highly recommended that all staff that has frequent contact with pigs should be vaccinated against influenza.

Diagnosis in oral fluids is indicated for the control of replacements on arrival and after the adaptation process, and of the different production batches, especially risk subpopulations such as animals with a slow growth rate.

Genetic and antigenic diversity of influenza virus should be understood as something dynamic and constantly evolving. So, it is crucial to encourage active surveillance of SIV in order to improve our knowledge of the SIV strains present in the European pig and their particular prevalence and impact in swine production.

It allows us to analyse virulence factors directly on the clinical sample, avoiding the intermediate stages of culture and determinations on each of the selected isolates, leading to considerable savings in time and costs.

Flies are not usually seen as a real risk of infection between farms unless we're talking about very high-density areas. However, flies can travel long distances if captured when collecting carcasses.

The author questions whether the US virus is more virulent than the strain CV777 isolated in Europe in 1977 or whether the disease is indeed more devastating now than it was in the seventies in Europe.

Recently, PCV2 has been suggested as a pathogen able to induce diarrhoea in pigs, and PCV2-enteric disease (PCV2-ED) as a separate entity within porcine circovirus diseases (PCVDs) has been proposed.

The most direct strategy to decrease the concentration in the air of airborne pathogens is dust reduction. This article describes the use of a particle ionization system called EPI.

Biosecurity measures for visitors should be implemented in all farms without exception, and hand washing with soap and subsequent disinfection should be compulsory in those farms where showering is not.

Influenza infections are self-limiting at the individual animal level with infection lasting between 5 and 7 days approximately. However, influenza virus is considered endemic in swine populations worldwide, and is not uncommon to find between 3 and 5% of pigs positive to influenza virus at slaughter.

How can we tell whether a transport vehicle is clean by just taking a glimpse?

The current situation for PED is that of continual occurrence of moderate to severe outbreaks in many pig farms, across Asia, USA and elsewhere, on both naïve farms and those that have suffered previous episodes.

The great genetic diversity of East European strains has practical implications, the sensitivity of some of the diagnostic PCR methods can be compromised and the efficacy of the current PRRSV vaccines against the East European genetic variants still needs to be elucidated.

At autopsy of some affected pigs, the soft gelatinous oedema was evident in the eyelids, but also in the meso-colonic area of the spiral colon.

We concluded an Edema disease episode, which is extremely unusual at this age.

Enric Marco tells us that of late, it is relatively common to see fattening pigs in their final phase exhibiting respiratory symptoms that respond poorly to antibiotic treatments. In these cases, we usually think of PRRS virus; however raising the possibility of a mixed viral infection is less frequent...

A definitive diagnostic evaluation of PRRS with respect to clinical disease requires that serological information be interpreted in combination with results from other virus assays.

PRRSV favours the appearance of secondary infections like the one caused by S. suis  due to the impairment of the alveolar macrophages cleaning functions.

Replacement gilts recently introduced and piglets prior to weaning are the main risk groups.

Carcasses showed a good body condition and a pronounced cyanosis in the area of the ventral abdomen and the ventral throat.

Surrounding holdings with high hedge fences reduces the risk of airborne transmission.

Today, nearly all genetic suppliers of replacement breeding stock in North America are free of M.hyo.

PCR is expensive relative to other diagnostic methods.It should be kept in mind that a positive result on PCR indicates the presence of viral RNA and does not necessarily indicate the presence of infectious PRRSV.

A perfect antigenic match is ideal because it will result in little to no virus replication/damage, shedding or clinical signs. However, if the virus is similar enough to have cross-reaction, the infection can be reduced to as few as 2-4 days.