Retrospective analysis of risk and timing of death from right heart failure in United States and Canadian feedlot necropsied cattle

OBJECTIVE To evaluate the risk and timing of right heart failure (RHF) in feedlot cattle. ANIMALS Study population consisted of 1,717,356 cattle (5,527 cohorts) in 13 US and Canadian feedlots. There were 1,336 RHF diagnosed at necropsy. PROCEDURES Multivariable models were utilized to evaluate risk and timing of RHF death. RESULTS Arrival year was associated with RHF and was influenced by arrival quarter on the magnitude of risk of RHF (P <.01), but no linear increase over years was identified. The impact of feedlot elevation on RHF was modified by breed (beef, dairy, or dairy-cross; P <.01) with beef cattle in the highest elevation category having 0.54 times the risk of RHF as dairy cattle in the same elevation category (LCL = 0.31; UCL = 0.962). Cattle that died due to RHF and were treated for bovine respiratory disease died 11 days (LCL = 1.33, UCL = 20.2 days) sooner than cattle never treated for bovine respiratory disease (P =.03). Cattle breed was associated with RHF timing (P =.01), and dairy-cross cattle RHF cases died approximately 37 days earlier (SE = 13.0 days; P =.01) compared to beef cattle.