Articles - Pig health

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.

PRRSV does not favour infection by H. parasuis by reducing the population of alveolar macrophages, but by reducing their ability to inactivate the bacteria.

This clinical case study tracks the long term pattern and control of Actinobacillus pleuropneumoniae (App) disease in a breeder feeder farm through the 1990’s.

App control is an essential link to control pleuroneumonia in PRRS-positive herds.

PRRS virus infection can be considered common in areas of high pig density and, in such cases, the idea that biosecurity and can do little is widespread. However, proper biosecurity measures must be implemented in order to prevent the introduction of new strains.

A relatively high proportion of young piglets in a farrowing unit of a herd with circulating swine influenza virus may be infected by SIV during the first weeks after birth revealing that not all piglets are protected by maternal antibodies.

This article proves that, at least "in vitro" order matters. In PRRSV/PCV2 mixed infections, the consequences are worse when PRRSV infection occurs before or concurrently to PCV2 infection, than when the sequence is reversed.

Any tentative clinical diagnosis then should be confirmed by detection of PRRSV (infectious virus, viral antigens and/or viral genomic material) in affected pigs using laboratory methods in conjunction with typical lesions.

Post-weaning colibacillosis and oedema disease are common global infection among farmed pigs – these strains of E coli appear to be "embedded" in most pig farms, so elimination is not a current option. Vaccination of sows or gilts with ETEC vaccines has no effect on post-weaning E. coli infections.