Structured Literature Review of Responses of Cattle to Viral and Bacterial Pathogens Causing Bovine Respiratory Disease Complex

Abstract

Bovine respiratory disease (BRD) is an economically important disease of cattle and continues to be an intensely studied topic. However, literature summarizing the time between pathogen exposure and clinical signs, shedding, and seroconversion is minimal. A structured literature review of the published literature was performed to determine cattle responses (time from pathogen exposure to clinical signs, shedding, and seroconversion) in challenge models using common BRD viral and bacterial pathogens. After review a descriptive analysis of published studies using common BRD pathogen challenge studies was performed. Inclusion criteria were single pathogen challenge studies with no treatment or vaccination evaluating outcomes of interest: clinical signs, shedding, and seroconversion. Pathogens of interest included: bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1 (BHV‐1), parainfluenza‐3 virus, bovine respiratory syncytial virus, Mannheimia haemolytica, Mycoplasma bovis, Pastuerella multocida, and Histophilus somni. Thirty‐five studies and 64 trials were included for analysis. The median days to the resolution of clinical signs after BVDV challenge was 15 and shedding was not detected on day 12 postchallenge. Resolution of BHV‐1 shedding resolved on day 12 and clinical signs on day 12 postchallenge. Bovine respiratory syncytial virus ceased shedding on day 9 and median time to resolution of clinical signs was on day 12 postchallenge. M. haemolytica resolved clinical signs 8 days postchallenge. This literature review and descriptive analysis can serve as a resource to assist in designing challenge model studies and potentially aid in estimation of duration of clinical disease and shedding after natural pathogen exposure.

Pathogenesis, Host Innate Immune Response, and Aerosol Transmission of Influenza D Virus in Cattle

“…T he bovine respiratory disease (BRD) complex is a significant economic and public health burden (1) that affects young bovines worldwide. BRD is triggered by the presence of one or several viruses and/or bacteria (2) that are favored by a set of predisposing factors such as altered state of the host immune system (3) and environmental factors (4). Respiratory viruses may induce the disease alone, as in the case of bovine respiratory syncytial virus (BRSV), or cause disease by initiating a cascade of subsequent events of immune suppression (3,5), damaging the respiratory epithelium (6) and the airway clearance mechanisms (7) and altering the local biofilms (8)(9)(10) and normal commensal flora, thus leading to complex secondary bacterial invasion (8,10,11).…”

Bovine Viral Diarrhea Virus–Associated Disease in Feedlot Cattle

“…In experimentally challenged, transiently infected cattle, the median minimum number of days until BVDv shedding was detected was 2 days. 25 The median peak of BVDv shedding occurred at 7 days after challenge with shedding ending at a median of 12 days after challenge. 25 In contrast, PI animals usually have a very high and persistent viremia, 26 and BVDv is shed throughout life from virtually all secretions and excretions, including nasal discharge, saliva, semen, urine, tears, milk, and to a lesser extent, feces.…”

“…25 The median peak of BVDv shedding occurred at 7 days after challenge with shedding ending at a median of 12 days after challenge. 25 In contrast, PI animals usually have a very high and persistent viremia, 26 and BVDv is shed throughout life from virtually all secretions and excretions, including nasal discharge, saliva, semen, urine, tears, milk, and to a lesser extent, feces. [27][28][29] Horizontal transmission of BVDv to seronegative cattle has been shown to occur after only 1 hour of direct contact with a single PI animal.…”

Status of the development of a vaccine against Mycoplasma bovis

“…The current evidence strongly suggests that in cattle M. bovis is a secondary pathogen and that the contribution of other respiratory pathogens must be considered [29]. Immuno-suppressive viral pathogens such as bovine viral diarrhea virus (BVDV) and bovine herpes virus 1 (BHV-1) have long been associated with M. bovis respiratory disease in Canadian feedlots [30][31][32][33][34].…”