Q & A on Treating Cattle for Bovine Respiratory Disease (BRD)
In this easy-to-read paper, youll learn about the common causes of BRD and how they relate to various disease situations, the economics of those situations, a disease concept known as "smoldering pneumonia", and what you can do to stay ahead of BRD.
Q. Which three bacteria are the most common causes of BRD?
A. Mannheimia (Pasteurella) haemolytica
Pasteurella multocida
Haemophilus somnus
Q. How do you know which one is causing the disease in the calves youre treating today?
A. Cant know for sure. Virtually 100 percent of BRD cases are multi-organism infections, with more bacteria invading as the disease advances.a
Q. What can happen if you dont kill all the bacteria involved?
A. Costly repulls and chronics, and most costly death loss later in the feeding period.
Q. So, what bacteria should you treat for?
A. All three common causes of BRD. Start early and use a broad-spectrum antibiotic.
Probable Causes of Bovine Respiratory Disease Situations
Acute Cases
Repulls
Chronics
Death Loss After 30 Days on Feed
"Pasteurella multocida is commonly associated with chronic BRD that is described as smoldering a low-level infection that doesnt make calves sick enough to be pulled. Affected animals continue eating and possibly gaining weight, while the infection continues to spread and cause extensive lung damage.
Often, such an infection does not become apparent until the animal breaks back with a more acute M. haemolytica infection. Or the infection may smolder long enough to involve a large percent of the lung before it becomes clinical. Often, clinical detection is too late in the disease process for treatment to be effective. Widespread mortality results." c
Economics of Bovine Respiratory Disease: Where the Dollars Go
| Disease Situation | Primary Economic Considerations |
| Acute cases | Treatment cost and labor |
| Repulls | Treatment cost and labor Retreatment cost and labor Performance loss |
| Chronics | Treatment cost and labor Retreatment cost and labor Retreatment cost and labor Performance loss Carcass value loss |
| Death loss after 30 days on feed | Treatment cost and labor Performance loss Carcass value loss Purchase price expense Yardage expense Feed expense Customer dissatisfaction* |
| *A concern of custom feeders |
Veterinarians and cattle feeders agree that approximately 66 percent to 75 percent of death loss occurs after 30 days on feed.d
What You Can Do to Help Stay Ahead of Bovine Respiratory Disease
| 1992 | 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | |
| M. haemolytica | 581 | 692 | 369 | 675 | 274 | 369 | 291 |
| P. multocida | 476 | 480 | 361 | 432 | 239 | 317 | 273 |
| State Laboratories | Independent Laboratories | ||||
| Organism | # Tested | % Sensitive | Organism | # Tested | % Sensitive |
| M. haemolytica | 923 | 99 | M. haemolytica | 586 | 99 |
| P. multocida | 726 | 99 | P. multocida | 402 | 99 |
| H. somnus | 184 | 99 | H. somnus | 66 | 99 |
Footnotes:
a Mayer, John, DVM, Midlands Consulting, Omaha, NE. Observations on the complexity of bovine respiratory disease. Animal Health Forum, Fall 1995.
b Personal communication, Dr. Robert Sprowls.
c Sprowls, Robert, DVM, PhD and Post, Karen, DVM, MS, Texas A&M Veterinary Diagnostic Laboratory, Amarillo, TX. An examination of four bovine respiratory bacterial pathogens. Veterinary Scope, Volume 2, No. 2, 1992.
d Data on file, Merck Animal Health.