Testing Is Not Harmful, And It’s Working, Says CFIA Senior Vet

“We use the best tools we have.”


The federal vet in charge of TB testing in the Riding Mountain TB Eradication Area dismisses claims by ranchers that the test could be making their animals sick.

Dr. Maria Koller-Jones says the argument that the existing testing process needlessly exposes ranchers in the RMEA to enormous collateral damage doesn’t wash, noting that all major livestock organizations fully support the CFIA’s efforts, from the MCPA, the Dairy Farmers of Manitoba, the CCA, and the cervid and bison associations.

The tuberculin used is sterile, protein extract, unlike a vaccine using live or modified virus, and is safe to use in pregnant animals.

It is “biologically impossible” for it to cause infection, abortions or failed conception, she added. Every batch is tested on guinea pigs – the animal most sensitive to TB of all species – before it is approved for use.

It is used to stimulate a localized, allergic response from the cow’s immune system that is intended to cause mild swelling or redness, similar the allergy tests used on humans.

As for the herd health issues raised by producers, Koller-Jones said CFIA testing is not the culprit, nor is it responsible for determining what might be the cause.

“The producers are in the best position to identify the various health problems that they might be encountering in their herds,” she said.

“I’m sure you could go into a herd that had never seen a CFIA inspector and a tuberculin syringe and you’ll see producers who have problems that could be caused by all manner of things, whether infectious disease, metabolic, nutritional, parasitic or management practices or whatever.”

The CFIA has no power to threaten local vets, she noted, and since it is in the business of animal health, it encourages producers to seek outside help. Non-vet inspectors hired by the CFIA to do the bulk of the screening test are fully trained and qualified to do the work, she added.

“There are always going to be complaints about government inspectors,” she said. “There are people who they don’t get along with as well as others; that’s just life.”

As for the issue of compensation for abortions or open cows, the Health of Animals Act does not provide for it, she said.

Koller-Jones said the eradication program that aims to eliminate bovine tuberculosis is working.

Since 2002, the CFIA has done roughly 180,000 TB tests in the Riding Mountain TB Eradication Area.

Of those, 4,745 “reactors” to the initial screening test in which tuberculin is injected into the animal’s tail have been found.

Those animals then went on to the Bovigam blood test stage. Of those, 225 were deemed to be “positive or suspicious” cases, and 194 were ordered destroyed so that tissue samples could be taken for confirmatory testing.

“I think some producers are happy to get those cows out of there, even if there is a little question mark because they could be the ticking time bomb next year with full-blown TB,” she said.

Of the samples taken from those animals, all but six ended up being negative. Five of the positive cases were found in 2002-03, and the sixth was found in May of 2008.

With so many false positives, how can the CFIA say that the existing testing program is working?

“There is no live animal test that can confirm with 100 per cent accuracy that an animal is infected,” she said. “We use the best tools we have.”

When the latest case was discovered, all the other animals in the herd were destroyed. Tissue testing of those animals found that all of them were negative.

“So there was only one cow with TB, and this testing protocol found her,” she said. “When the disease is present at a really low level, you are going to have a false positive problem.”

Some of the 194 animals ordered destroyed weren’t found to be positive, but that doesn’t mean that they didn’t have it. It could have been too early in the incubation stage for the pathogen to be detected.

“That’s just the way TB is,” she said. “We don’t culture all 1,000 pounds of the carcass, we just take little samples from different parts of the body. If the infection is tucked into a corner of lymph node that we haven’t sampled, it’s going to be negative.” [email protected]

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