Flipping through a few favoured agricultural websites it was interesting to see yet another disease is threatening the Canadian hog sector.
In this case its the possibility of porcine epidemic diarrhea (PED) crossing the border from the United States.
“PED was discovered in the U.S. nine months ago and has since killed three million pigs,” detailed a Western Producer story. “It is believed to have affected 15 to 20 percent of the U.S. pork industry, causing millions of dollars in damage.”
That there is a disease issue hog producers must deal with is nothing new.
I grew up on a hog farm, and even in the later 1960s and early ’70s the impact of disease on production was becoming recognized by producers.
At the time Atrophic Rhinitis was the disease producers were most aware of. The disease is an inflammation of the tissues inside the nose and in its mild form it was likely in most herds by the end of the era. The concern was when the disease became more serious, a situation where noses would actually twist, making eating more difficult, and becoming a factor in some secondary respiratory diseases.
The era was one where producers were becoming more aware of the idea of biosecurity. It was usual then for producers to ask visitors to their barns to change boots before entering the barns, or at least walking through a disinfectant bath in an attempt to stop disease transfer.
There was still many producers, at least those in the seed stock business, who would attend shows, a place where pigs interacted with each other in the barn and show ring over several days. It was likely the animals were introduced to more than a few bugs in such situations.
Of course back on the farm sows were usually kept outdoors except when farrowing. At the time most farms were still mixed operations, many having at least a few hogs. That meant magpies, other birds and vermin most likely carried a few pathogens from farm-to-farm.
There was a school of thought at the time whereby producers felt disease was somewhat inevitable much like we as humans are going to catch a cold no matter what precautions we take.
Those of us who are healthy, and have come into contact with as many bugs as possible build up a natural defence to the cold.
Some producers thought hogs were better off developing the same natural defences.
But hog operations evolved through the late 1970s toward ever larger operations, operations where all animals were taken indoors, the doors locked and the idea of high level biosecurity implemented, an evolution made in the face of new diseases such as leptospirosis and Porcine Reproductive & Respiratory Syndrome were shown to have an economic impact.
Most modern barns no longer admit visitors, meaning only staff, and those with a reason are allowed, and they are often required to shower-in, wear provided clothing, and then shower-out.
The system makes sense if no bug ever breaks the barrier of defence.
But it is very difficult to deal with every possible entry point of disease. Birds and vermin may be less of an issue since barns are now generally much further apart, but feed trucks, trailers used to get hogs to market, or new breeding stock are just some of the areas a disease might enter a barn.
And once inside an operation there is likely to be very little natural disease resistance because so much effort has been made to prevent introduction of any pathogen.
This is not to suggest the current high level biosecurity of hog barns is wrong, but in my mind at least now that there are reported cases of PED in Canada.
The hogs in such operations are likely to be hit hard, and could be devastating to the hog industry if we don’t act quickly to keep it contained. •
— By Calvin Daniels