When it comes to Bovine Respiratory Disease Complex, it’s important to use all the weapons at your disposal… because the bugs have got you outnumbered.
“There’s four different viruses — IBR, BVD, PI3 and BRSV — that cause problems with respiratory disease in cattle,” Dr. Jeremy Powell, University of Arkansas Cooperative Extension Veterinarian and Professor of Animal Science, said. “And then, there’s about five different bacteria.”
Calves are susceptible when environmental stress — weather or recent handling, for instance — lowers their natural defenses; this creates an opening for a viral infection that can eventually lead to bacterial pneumonia, which Powell said “can cause some real severe issues, and even death in calves.”
The clinical signs are generalized to start with. Powell said among them are lethargy, weakness and poor appetite; that’s accompanied by a fever of 104° or greater, and an increased respiratory rate. “And you’ll also see a depressed appearance to the animal,” he said. “They’ll have a lowered head and ears; they may be showing some nasal discharge or ‘snotty nose,’ and some soft coughing may be apparent, too.”
But don’t be surprised if you can’t detect the problem at first glance. “Cattle for the most part are very good at hiding physical signs of illness,” said Powell. “Because they are a herd animal, and do not want to stand out from the other cattle, they’ve evolved to hide symptoms of illness… Sometimes disease has progressed two or three days before we start to see some of these negative symptoms.” That means you’re already behind schedule as far as treatment.
Powell said that usually involves a prescription antibiotic; he recommended against over-the-counter drugs like penicillin, oxytetracycline or sulfa. “Those drugs are less effective for treating respiratory disease,” he said, “and you don’t want to make the mistake and think by purchasing those drugs, which are typically less expensive, that you’re going to do the animal justice using those medications.
It’s best to go ahead and get a prescription product from your veterinarian.” At U of A’s stocker cattle unit, which often sees calves that are seriously ill, they may use a multiple antibiotic regimen. After the initial treatment, the calf is evaluated over the next 48 hours; Powell said 80-85 percent of the animals respond to the first treatment and are turned back onto pasture. “If they’re not better,” he said, “we use a treatment regime of two additional antibiotics. They are going to get a second antibiotic injected approximately 48-72 hours after the first one, depending on the time frame based on the indications on the label of the first antibiotic that we used. If they’re coming along nicely and improving, then they go back to pasture; if they don’t, then they get a third and final antibiotic injection at that point.”
If you don’t get an 80-85 percent response to that first treatment, said Powell, “then you’re probably not identifying the sick cattle early enough, and treating early enough. The faster you get antibiotic therapy into them, the more likely you’re going to have successful recovery from the disease, so identifying the problem early is a real key to try to be effective in combating the issue.” And the chance of having a problem to start with can be reduced through vaccination.
Powell said it’s common to inoculate animals against the complex of respiratory viruses; in fact, IBR and BVD can also cause abortion, so the U of A Cooperative Extension Service recommends vaccination of mature cows as well. He added, “And we also recommend that you come back and vaccinate your calves at about 3-4 months of age with a a five-way viral vaccine; most vaccines have the four respiratory viruses, and two types of BVD are contained in the vaccine.”
In addition, if respiratory problems have been a major issue in your operation, you may want to consider vaccinating against Pasteurella bacterin. That’s “less common for producers to use,” Powell said, “but if you’re having problems with the disease, it may be a good idea to put that in your vaccine regimen.”
