Now more than ever it’s critical that feedlots identify, diagnose and treat sick cattle as specifically as possible. It’s no surprise that this starts with pen riders. R. Kent Fenton, DVM, Feedlot Health Management Services Ltd., Okotoks, Alberta, Canada, says the first step is a subjective evaluation by pen riders in the home pen; and the second step is an objective measurement of rectal temperature.
The pen riders differentiate between clinical cases of BRD and other disease syndromes such as gastrointestinal disease, nervous disease, lameness, etc. Animals that are pulled for treatment for BRD have clinical signs which include depression, and, these animals generally do not have clinical signs referable to body systems other than the respiratory tract. “Once these cattle are presented for treatment we refine the diagnosis and subsequent treatment protocol by categorizing them further based on rectal temperature,” Fenton explains.
“In my experience the best pen riders in the best work environments become quite passionate about the requirement to correctly identify the different disease syndromes that may affect feedlot cattle,” Fenton says. “These highly skilled pen riders seem to innately understand the importance of having treatment protocols assigned specifically to sub-groups of cattle with clinical BRD. We help them accurately identify the different disease syndromes by providing them with training and education, and a user-friendly software system.” He explains that this education can include the results of analyses specific to them and their feedlot so that they have an opportunity to learn from their previous experiences. “This definitely helps with buy-in.”
Based on the subjective assessments performed by pen riders, cattle that are severely ill with BRD may be separated from the other animals once they reach the hospital environment in an effort to reduce their crowding, allow closer monitoring of their condition, etc. “In addition, cattle that have been treated repeatedly for BRD without recovering (non-responders) are deemed to be chronically ill with BRD and will be separated and housed in small pens to provide them with shorter distances to feed and water, less crowding and easier monitoring by their caretakers. Also, this segregation of non-responders has the potential to assist with biosecurity in the feedlot,” Fenton explains.
Cattle sick with BRD have their treatment protocols determined by their rectal temperature. Predetermined cutoff values are used and the protocols are presented on the chute side computer system. “The case fatality rate of BRD cases with different rectal temperatures is monitored and treatment protocols may be adjusted if deemed appropriate,” Fenton notes.
Categorizing sick cattle allows treatment protocols to be developed that are more effective for smaller groups, rather than for just the big group of “sick cattle,” Fenton says. “The goal of any system used for treating cases of BRD should be to maximize the important health outcomes, especially mortality. Cattle sick with BRD can be placed in categories for which the assigned treatment is most efficacious and cost-effective. This refinement of case definition is consistent with our overall goal of managing animals individually when applicable strategies can be validated by positive outcomes.”
”We know that not all cattle entering a feedlot are at the same risk of becoming ill due to BRD,” Fenton says. “We can predict which cattle have higher or lower risk of developing BRD, even prior to arrival, based on well-documented risk factors including source, commingling, age, etc. Categorizing feedlot cattle on arrival based on their risk of developing BRD, and subsequent monitoring of health indices, facilitates the use of different, specialized protocols. The same general concept holds true for new BRD cases in a feedlot, where we know that case fatality rate increases with elevated rectal temperatures. If we were to not refine the case definition of BRD we would run the risk of recommending less effective treatments in some cases.”
All treatments administered to an individual animal are tracked using the animal’s unique identification numbers. Records of these treatments are then accessed real-time from the on-site health database by the pen riders or hospital crew each time an animal is in the chute for treatment. As a result of having this information available chute side, the treatment recommendations that are presented are refined in response to information such as the number of previous treatments administered, explains Fenton.
“I think it is very important that we continue to refine and validate our diagnostic techniques, treatment protocols and evaluation processes as new options are developed.” Fenton says. “I feel that as veterinary professionals it is incumbent on us to pursue further excellence in these matters for reasons of protecting animals, the public and the well being of our clients’ businesses. In fact we are presently involved in two research projects where the objectives are to test whether newer modalities can be used for the diagnosis of BRD early in the course of the disease. If these technologies are successful in the feedlot setting, then we may have an opportunity to further categorize some of the populations of sick cattle that we treat for BRD. And then from there we may be able to further refine treatment protocols, including the use of antimicrobials.”