Tuberculosis awareness is critical for cattle producers

Published on Feb. 15, 2020

Most often associated with dairy cattle, bovine tuberculosis (TB) can find its way into beef herds and awareness is key for prevention. 

            On a recent episode of Doc Talk with Dr. Dan Thomson, veterinarian and head of Iowa State Animal Science Department, Thomson invited Kansas Assistant Animal Health Commissioner Sarah McReynolds to discuss TB and how it can affect cattle producers across the board. 

Rise and fall of TB

            “I really didn’t know much about TB until I became a regulatory veterinarian and began looking into USDA programs through the early 1900s and TB was one of the first programs,” she explains. “We have nearly eradicated TB in the U.S. due to pasteurization of milk and testing.” 

            She continues, “But as cattle are moving more and the popularity of products such as raw milks and cheeses rise, the instances of TB have risen.” 

            “We are still seeing sporadic herds pop up around the country that test positive for TB,” she says. “It is spread through direct contact, but it’s what we know as a long disease, meaning cattle can carry it for a long period of time before showing any symptoms.” 

            She continued, “Cattle could be shedding the bacteria for years and we would never know it. They can come into contact with it through respiratory droplets or contaminated feed and water.”

            She explained beef products don’t pose as high of a public health risk as dairy products, as pasteurization of milk plays a key role in killing the bacteria. 

            “The biggest threat of spreading TB from cattle to humans is from the consumption of unpasteurized milk, but beef producers should still pay close attention to their herds,” she said.

Spreading TB 

            “Too often, when we think about zoonotic diseases, we think only of animals spreading the disease to humans and not the other way around and this just isn’t true with TB,” she explains. “Bovine TB can be spread to humans, but we can also give it to cattle. There are documented cases where human workers gave TB to cattle.” 

            “As someone who is intercating with cattle a lot, if I leave the country for any reason, I get a TB test when I get back, especially in countries with an unknown TB status,” she said. “If producers are hiring employees or seasonal workers from countries where TB is common, it is advised to have them get tested.” 

            She noted the most common origin of TB in beef cattle is those coming from Mexico. She stressed the importance of getting any animals tested to prevent the introduction of reactor animals being introduced into the herd. 

            “A lot of times when we see TB issues at a packing plant, it is with cattle from Mexico,” she says. “Once

Callie Hanson is the managing editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.