From the State Vet's Office
by Dr. Tony Frazier
I remember as a child watching a particular western movie — John Wayne, I think. Anyway at some point in the movie one of the cowboys said to another, "Son, you’ve just bought yourself a peck of trouble."
I wonder what a peck of trouble looks like. I suppose it could look like any number of things, like a basket full of rattlesnakes or snapping turtles to such intangible things like bad will between a couple of cowboys. One thing is certain, trouble is still out there on the open market and people are still buying it.
I want to spend a little time talking about the kind of trouble livestock producers can purchase in the form of disease. Bringing disease into a herd of livestock is costly, but with some firewalls in place, can be highly preventable.
It is not an uncommon practice to purchase a new horse or a few cows or calves, and if they look healthy, to go ahead and turn them out into the pasture. I can recollect many times when that practice has led to an absolute train wreck. Often animals that have been through a sale have been stressed to some degree and at the same time exposed to various viruses. The purchased additions, like the old Trojan horse in Greek history, seem fine to be brought into the herd. Then a few days later, several animals in the herd become ill.
I know some of you reading this article now are thinking of the time you bought a horse that gave most of the herd strangles. Others, or even the across-the-fence neighbor, have bought calves that gave the whole herd a respiratory illness.
The examples previously given are very real and fairly common. They are expensive, time consuming and frustrating. However, those situations can usually be worked through with enough time and pharmaceuticals. There are other times when producers "buy trouble" that cannot simply be worked through. There are diseases like Johne’s disease, anaplasmosis, Equine Infectious Anemia (EIA) and Brucellosis that can be considered "purchased diseases. These diseases are not brought in by wildlife or on the shoes or clothing of farm visitors, nor do they just float in on the prevailing winds. They come in through healthy looking animals, later to make their way into the herd and establish residence.
Two of the diseases, EIA and brucellosis, are regulated diseases and require some quarantine, further testing and, at least, some depopulation, if not the complete herd in the case of brucellosis. The problem with anaplasmosis, an infection attacking the red blood cells of cattle, is not so much the acutely sick animal but the animals that are chronic carriers, yet are not sick. These carriers seem to be an adequate reservoir for the disease to be transmitted to susceptible animals through ticks, flies and anything else transferring blood from cow-to-cow, like used hypodermic needles.
Then there’s Johne’s disease, a chronic, incurable, wasting diarrhea in cattle. Johne’s disease is a very difficult disease to corral because of the causative organism’s ability to exist in the environment for up to several weeks. Therefore, simply testing and culling positive cattle will not necessarily clear up the problem. Another obstacle in ridding a herd of the disease is a calf may be infected with the organism at a very young age and not only not show signs of illness, but may continue to test negative for the disease until it is much older. When Johne’s disease invades a herd, the process of clearing the herd may be extremely difficult. The disease is probably more of a problem in dairy cattle because of management practices that concentrate cattle and calves. Nevertheless, Johne’s in a beef cow herd can be, and usually is more than just a hindrance. A decrease in milk production in otherwise healthy cattle is common in both beef and dairy cattle and lowers the bottom line. Sometimes the truly sick cow that wastes away because of the chronic diarrhea may only be the tip of the iceberg.
There are some management practices that can be employed to keep the risk of introducing a new disease into the herd. First there is quarantine. This is not a legal government-issued quarantine, but one that the producer uses to keep new animals separated from the other animals for a period of time — say 2-4 weeks. Another tool possibly used is to require testing for certain diseases before adding animals to your herd. You may require a negative Coggin’s test on any horse you purchase or a negative Bovine Viral Diarrhea (BVD) before adding cattle to your herd. You may want to try to purchase replacement stock from someone with whom you are familiar and know the history of their herd health. Other sales require certain negative tests before allowing the animals into the sales. These along with good biosecurity measures can go a long way in keeping your herd healthy.
Finally, it is worth mentioning that even using best management practices, sometimes breaks occur and new diseases are introduced. Still the old saying about "the best offense is a good defense" remains true. And being from the South Eastern Conference, we know defense wins ballgames. Well, it also keeps diseases out. There is still trouble out there that can be bought, but sometimes you would probably be better off with a basket full of rattlesnakes or snapping turtles.