In the last issue we introduced the topic of bacterial pneumonia in cattle and discussed the significance of the disease, the basic mechanisms involved that result in pneumonia and effective prevention strategies. In this issue our focus will be on prompt and accurate diagnosis, followed by currently recommended treatment protocols.
Bacterial pneumonia can occur in any class of cattle. However, pneumonia is most common in younger cattle. It is estimated that about 1/3 of calf losses from 3 weeks post calving to weaning are a result of pneumonia. Furthermore, approximately 80 percent of death loss in stocker and feedlot operations is attributable to BRD. Therefore, in regards to making a diagnosis of pneumonia, considering the class of cattle in question is a major factor. The history of the animal can also be a big clue. Animals that are well vaccinated and managed and handled to minimize stress are less likely to suffer from BRD. In contrast, if a sick calf presents with a history of recent weaning, a long haul to a sale barn and commingling with a group of similar calves, a producer would be pretty safe to hang his hat on a diagnosis of pneumonia until proven otherwise.
Of course, age and history are only part of the story when making a diagnosis of BRD. Producers should be familiar with the classic presenting signs of pneumonia. Early in the course of disease, cattle are first identified as depressed, off feed, potentially off from the herd and frequently standing with their head and ears dropped and neck slightly extended. Labored breathing and increased respiratory rate is a giveaway. Nasal discharge is common and cattle will frequently cough especially when forced to move or run. When examined, calves will frequently run a high fever and harsh lung sounds are apparent.
With the appropriate age, history and clinical signs, producers can strongly support a field diagnosis of pneumonia. For a definitive diagnosis, a trans-tracheal wash can be performed by your veterinarian to obtain a sample for culture and antibiotic sensitivity testing. Post-mortem samples can also be submitted for similar testing. This gives producers and veterinarians the ability to identify the exact organism responsible for disease on their farm, and the most effective antibiotic to be used for treatment.
There are numerous antibiotic drugs labeled for use in the treatment of BRD. Commonly recognized over-the-counter antibiotics include penicillin and oxytetracycline (LA 200). Unfortunately, these antibiotics at labeled dosages have shown evidence of pathogen resistance and prescription antibiotics provided under a relationship with your local veterinarian are much more successful in treating cases of BRD. Today’s prescription antibiotics provide excellent efficacy and extended therapy options that frequently result in single treatment cures. This not only provides convenience for the producer but also minimizes cattle handling and subsequent stress on the animal. Prompt treatment upon recognition of clinical signs and treatment with an effective antibiotic is the mainstay of therapy. Non-steroidal anti-inflammatory drugs (NSAIDs) such as Banamine can improve treatment success when administered early in the course of disease. Other adjunct therapies including vitamin injections have not shown much evidence in improving treatment outcome.
Significant information is available for producers to further educate themselves on bovine respiratory disease. This two part series is meant as an overview and has hopefully provided readers with a general understanding of BRD and preparedness for effective intervention on the farm.
Darren Loula, DVM, is a large animal veterinarian at Fair Grove Vet Service in Fair Grove, Mo.
