EDMONTON – The case of the cow with BSE could be a novel written by British mystery novelist Agatha Christie. Instead, it’s a true-life story that Canadian veterinarians had to deduce in a race against time.
Canadian Food Inspection Agency staff had few clues when they got the call May 16, just before the Victoria Day long weekend, that a cow had tested positive for bovine spongiform encephalopathy, said George Luterbach, a CFIA veterinarian.
They knew the remains of a black cow had gone to a rendering plant three months earlier and the hide had been stripped and sent to a tannery.
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That basic knowledge launched parallel investigations within CFIA. Investigators had to find out what happened to the animal and where it had come from.
By talking to Marwyn Peaster, the Peoria, Alta., area farmer who took the cow to slaughter, they learned the animal was “crazy.” It had been aggressive, but there had been a regression of the signs. By the time it was sent to slaughter it wasunable to rise.
They knew Peaster was a former American catfish farmer.
“You say, ‘why is that important?’ We know that if you’re a catfish farmer or a fish farmer, you’re used to using a lot of prepared feeds. So he might have been experienced, to put in context the experience of this Alberta farmer, with feed,” Luterbach told a BSE update meeting for the Alberta Association of Municipal Districts and Counties.
Investigators also learned that Peaster moved to Alberta to start a herd in 2001.
“Why that was really important was, number one, he did not have a lot of experience raising cattle, but even worse, his herd all came from somewhere else.”
Four days after the initial positive test for BSE and three more confirmations at laboratories in Winnipeg and England, federal agriculture minister Lyle Vanclief and Alberta agriculture minister Shirley McClellan broke the newson May 20 of Canada’s first domestic case of BSE.
With limited knowledge, investigators fanned out searching for animals that may have been associated with the cow. BSE is not a contagious disease, but they were looking for clues of similar feed or similar family ties. Before the investigation was completed three weeks later, 2,700 cattle in British Columbia, Saskatchewan and Alberta had been slaughtered in an attempt to leave no doubt that Canada’s first domestic case of BSE was its last.
Through the investigation they discovered some of the weak points in Canada’s cattle industry.
By checking ear tags they discovered Peaster had taken 30 cows to a community pasture, but when the animals returned home he had 29 of his own and one from another owner.
“It proved there was some slippage in animal identity,” said Luterbach.
Through livestock manifests and animal identification, investigators were able to identify seven adult cows as being the likely source cow.
They also learned in their search for the remains of the BSE cow that there are weaknesses in records regarding the destination of ruminant-made feed.
CFIA officials interviewed 600 producers over the phone who may have bought feed containing the remains of the original cow. Out of those 600 producers, they identified 100 as being at a higher risk. Many of them had farms or acreages where multiple species were fed.
“If you had hogs or chickens you could legitimately be feeding rations containing ruminant protein to those animals. If you happen to have a few cattle on your place, and you didn’t know better, you might be tempted to feed some poultry ration, or chop from the hog ration, to the cattle,” said Luterbach.
“We had to verify whether that was being done or not.”
Unfortunately, there were a few incidences. On one farm feed was spilled in a pasture. In others a goat had access to a feedbag, cattle broke into the feed barn and sheep had access to a hog trough along a fence line. Because of that cross contamination of feed, 63 head were killed and tested.
While investigators were tracking down the cow and its origins, another team was looking at where the BSE had come from.
Canada and the United States had imported animals from the United Kingdom until 1990. In 1993 one of those animals, a Salers cow near Red Deer, tested positive for BSE. The entire herd and all the cattle imported from the UK between 1980 and 1994 were destroyed.
But before the Salers cow was discovered, a number of the imported animals died from natural causes or were sent to slaughter for some reason. Some of those animals could possibly have had BSE and entered the feed system. The story is similar in the U.S. where cattle imported from the United Kingdom may also have entered the feed system.
Officials estimate only 16.6 percent of the cows in Canada today were around when the feed ban went into effect in August 1997.
Imports from the U.S. have steadily increased over the years, especially with the implementation of the Restricted Feeder Cattle Program that allows cattle to be fed in Canadian feedlots as long as they go directly to a slaughter plant.
In the second year of the program, some Angus-type cattle entered the Canadian herd and did not go to packing plants from the feedlot.
Canada imports more than 30,000 tonnes of meat and bone meal from the U.S. and contaminated feed may also have entered from there.
Investigators looked at the impact of chronic wasting disease and what impact it may have had on BSE. Many of the CWD cases in farmed and wild elk were in the same area where the BSE cow was believed to have originated.
While officials didn’t believe there was a connection, they had to make sure.
“This was a world class investigation. It had to stand up to the scrutiny of the world. People are going to ask ‘did CWD play a role?’
“The good news is when we sent the sample away to Cambridge, England, we asked them to check that out for us. They pointed out that this was not CWD. It was typical BSE and furthermore, it was as close as they could tell, exactly the same BSE found in the UK,” said Luterbach.
Knowing the length of incubation of the disease and when the feed ban was implemented and the age of the cattle most susceptible, investigators knew 2003 was the year with the highest risk for the disease.
“Unfortunately, it was also the year it was found.”
