In this session we will take an evidence-based medicine approach to ancillary therapy of bovine respiratory disease. The literature
reviewed here is not presented as being all-inclusive, but rather as a summary of many commonly cited articles on these subjects.
The citations are primarily peer reviewed, but some are from freedom of information (FOI) summaries and a few are proceedings
papers or abstracts.
The question of ancillary therapy of BRD arises from these data, generated during the National Animal Health Monitoring System
(NAHMS) Feedlot Study conducted in 1999.
No published data could be found to support the use of Vitamin B or C, vaccines (at the time of therapy), antihistamines,
anthelmintics, probiotics, or oral electrolytes in the ancillary therapy of bovine respiratory disease. For the purposes of
this presentation, we will examine the published data concerning the use of steroidal and non-steroidal anti-inflammatory
drugs as ancillary therapy for respiratory disease.
Glucocorticosteroids? Decades after publication of the study described here, there is still only one published clinical trial addressing the use
of steroids for ancillary therapy of BRD as you would encounter it clinically in the United States. One of two treatments
was administered to animals identified as displaying clinical signs of BRD. Common drugs for the two treatment groups included
IV oxytetracycline (5 mg/lb) and IM pyrelamine (250 mg total dose) on a daily basis for 3 days. Treatment group 1 also received
20 mg dexamethasone every day while treatment group 2 received a 10 ml placebo injection. The same treatments for each group
were continued through day 9, as needed, for non-responders. Response was significantly different at P ≤ 0.05 and relapse
rate was significantly different at P ≤ 0.01.
These findings aren't that surprising since dexamethasone, at 0.04 mg/kg daily (0.9 ml/100 lbs of a 2 mg/ml solution) for
3 days, is used as a research model to suppress neutrophil function in cattle. This model was utilized in small Holstein calves
in conjunction with induced Haemophilus somnus pneumonia to demonstrate that this dexamethasone regimen increased lung lesions.
An IBR latency model in rabbits demonstrated that a single high-dose injection of dexamethasone (2.8 mg/kg) could bring about
reactivation of latent BHV-1. Other studies have failed to show significant differences in treatment response using prednisone
acetate, methyl prednisolone, or methyl-prednisolone-succinate in natural and induced respiratory disease.,
Non-Steroidal Anti-inflammatory Drugs (NSAIDs)
The NSAID currently labeled specifically for BRD in the United States is Flunixin meglumine (Banamine? Injectable Solution,
Schering-Plough Animal Health). The label includes indications for the control of pyrexia associated with bovine respiratory
disease, acute bovine mastitis, and endotoxemia. The inflammation indication on the label is for the control of inflammation
in endotoxemia. Flunixin meglumine is considered an effective analgesic, anti-inflammatory, and antipyretic. The mechanism
of action is cyclooxygenase inhibition.
The outlines below summarize published studies and the Freedom of Information (FOI) summaries of flunixin meglumine effects
on respiratory disease outcome.
Flunixin BRD study 1: 12 week old dairy calves, induced Pasteurella haemolytica pneumonia 4 treatment groups - no treatment,
oxytetracycline (10 mg/kg IM SID for 3 days), flunixin meglumine (2.2 mg/kg IV SID for 3 days), and both oxytetracycline and