As the Bovine tuberculosis (TB) episode in Southern Alberta unfolds, Montana cattle ranchers may ask, “what does this mean to us?”
As of Monday, November 28th, according to the Canadian Food Inspection Service (CFIS) 22,000 cattle are quarantined with 10,000 destined for slaughter with 1200 already euthanized. The quarantine and stop movement placed on the 22,000 cattle and 40 premises by the CFIS is particularly hard on ranchers during the fall, when the year’s calf crop would usually go to market, leaving ranchers without their major source of income. Many of the quarantined ranches are not set up for feeding and watering calves through the winter.
Bovine TB is zoonotic, meaning it can be transferred between animals and humans. State and Federally inspected slaughter facilities in the USA inspect each carcass post mortem to ensure no TB infected cattle reach the food chain. Any cattle suspected of TB are then traced back to their place of origin and the other cattle in the herd and any other herds that may have been exposed are quarantined and tested. Bovine TB is spread via inhaled airborne bacteria which can remain airborne for several hours, bacteria carried in manure, urine, or vaginal discharge. TB is also spread by entering open areas of the skin, or consumption of non-pasteurized milk from infected cattle.
To see such a large number of ranches and livestock under quarantine within a couple hundred miles is concerning, but this situation can also be studied and learned from. Here are a few thoughts to take away from the Canadian bovine TB event according to Montana State Veterinarian, Marty Zaluski.
In the USA, a federal/state cooperative effort to eradicate Bovine Tuberculosis was started in 1917. While TB has been almost eradicated in United States livestock, there continues to be sporadic cases found due to imported cattle and infected wildlife. California, Texas and Michigan have suffered repeat infections. This underlines the importance of continued inspections in the slaughter facilities.
While 10 cases of bovine TB have been detected post mortem at slaughter houses in the U.S. this past year, only this one case traces back to Canada. Canada and the U.S. both have strict testing requirements for importing cattle, while working hard not to restrict international trade. Canada Food Inspection Agency (CFIA) has put very strict quarantine and stop movement conditions on the herds that have possibly come in contact with the infected cow from Jenner, Alberta. While this is an extreme hardship on those families’ operations it is necessary to keep surrounding herds health secure and maintain international trade. Alberta cattle currently being imported should not be viewed as a threat to the health of Montana cattle.
We should look at and recognize the helpfulness of the Canadian livestock ID system in helping to trace the TB positive cow that was found at the US slaughter facility and all the cattle that she had been in contact with. By having that cow permanently identified and her movements on and off the premise monitored, the investigation could focus on animals at risk and avoid costs and hardship caused by testing unrelated operations.
Though Alberta does have a bovine TB reservoir in the Wood Buffalo National Park, in northern Alberta, the elk from the Canadian Forces Suffield Base near Jenner, Alberta are not known to be TB infected. Also, the strain of TB that was cultured from the discovered cow was a strain that has not previously been found in Canadian wildlife or cattle and is similar to a strain from Mexico. This would suggest that it was brought to Alberta by an imported cow that was exposed to the disease or the extremely remote possibility of a Hispanic worker who carried the disease. In the future there will likely be increased monitoring of the Albertian wildlife for TB, but the current focus of the investigation will probably remain on tracing possible cattle origins.
Montana ranchers should assess their current bio security efforts to be pro-active in reducing the possibility of introduced disease to their herds and mitigate losses if it should occur.