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| Confined hogs spend more time in contact with infected feces. By: Dan Gaskins and Mark Tyson, M.S. |
What causes PEDv and similar
diseases to spread rapidly in a domestic swine population is confinement.
Domestic swine can spend a good deal of time in contact with infected feces
because they are confined to a single space. Feral swine are not confined and
can cover miles in the course of a day, reducing the amount of time they spend
in contact with feces. There is the potential for the disease to spread in
wallowing areas where the animals tend to concentrate and spend time at the
same location. Feral hogs that do contract PEDv could die, but it is unlikely
that enough of the population could become infected to have a significant
effect on the population.
Commercial domestic swine
facilities have extensive biosecurity measures that prevent feral hogs from
entering and transmitting diseases, including PEDv, to the domestic pigs.
Transitional herds, such as show pigs, lack these measures and are at risk. For
a feral hog to transmit PEDv to a transitional herd, however, the pig would
have to enter the pen and defecate, exposing the domestic pig to infected
feces. While this is far less likely than diseases such as swine brucellosis,
which are spread nose to nose and venereally, it is possible.
PEDv has made the news recently in
an exclusive
report published by Reuters. According to the article’s author Tom
Polansek, PEDv has killed up to 7 million pigs (domestic) in the U.S. since it
was first identified one year ago. In the exclusive report, information was
publicly released confirming multiple outbreaks of PEDv on an Indiana pig farm.
These multiple outbreaks are especially concerning for swine producers.
Traditionally it was assumed that once a pig was infected and developed
immunity reoccurrence would not be a problem. Yet recent news given to Reuters
from the American Association of Swine Veterinarians confirms that there is a
likelihood that repeated outbreaks could occur. It is currently unclear why
re-infections are occurring and additional investigations are needed to address
this issue.
In short, PEDv will likely have a
limited effect on feral hogs due to a low chance of infection. There is some
risk that infected hogs could transmit the disease to transitional herds,
however, this will likely be relatively rare. Other diseases that are more
easily spread, such as swine brucellosis, pseudorabies, tularemia, and
leptospirosis, are a much greater threat.