By Doug Schmitz Iowa Correspondent
ATHENS, Ga. – A new report is urging U.S. farmers and livestock handlers to update their health and safety practices for bovine anaplasmosis, a blood-born disease that is carried from one animal to another through blood-feeding flies and ticks, or with contaminated tools during herd health processing. The disease is characterized by severe anemia and can lead to reduced production, abortions, and even death in affected animals. Jason Duggin, University of Georgia beef extension specialist, who authored the report, said one of the most important steps in preventing this disease is using a new needle for every injection. “In the past, we have often said that it is an acceptable practice to use a needle up to 10 injections if it doesn’t dull or become contaminated,” he said. “With the continual spread of anaplasmosis in the region, the best practice is to use a new needle for every injection. “It’s more than just delivering a pharmaceutical product in a humane way, while reducing lesions and abscesses,” he added. “Possibly now more than ever, it is a matter of herd health. To maintain herd health and profitability as bovine anaplasmosis continues to spread, we will need to change how we approach needles, castration, dehorning, implanting, and parasite control.” He said, “At this point, scientists believe that ticks are the major contributor. However, there are multiple strains of the bacterial organism known as ‘A. marginale’ that live in the red blood cells of infected cattle. Some strains are carried by ticks, while other strains are more commonly carried by blood-feeding flies.” According to the National Institutes of Health (NIH), bovine anaplasmosis is endemic in many parts of the U.S., particularly the South, Midwest and the West. States like Kansas, Oklahoma, Missouri and Arkansas have reported increases in bovine anaplasmosis cases, particularly in herds near rivers and in humid climates. Grant Dewell, Iowa State University beef extension veterinarian, told Farm World, “In most cases, the disease is transmitted by insect vectors (insects that transmit pathogens, such as viruses, bacteria, or parasites, from one host to another) such as ticks and biting flies, so if you are in an endemic area and your herd is clean, your biggest risk is insects and needle transfer is minimal. If you have carrier animals within your herd, then needle transfer may spread the disease, but insect activity is still probably more of a risk. “Single-use needles are a good biosecurity practice in most situations, but probably the biggest return is in dairy herds where they give more injections and where they can’t control the disease by feeding chlortetracycline (an antibiotic used in cattle feed to treat or control various diseases, approved for use in feedlot cattle to treat or prevent respiratory disease and for liver abscess control) during the vector season to limit disease transmission,” he added. “We generally consider the southern part of Iowa as endemic, anywhere south of I-80, and I assume that Missouri is endemic, and I know most of Kansas is. “In these areas, beef producers are commonly using chlortetracycline in the summer to help control the disease,” he added. “The University of Missouri recently produced a new effective anaplasmosis vaccine, but I’m not sure that is available yet.” He said, “Generally, with some intensive prevention and treatment strategies (i.e, single use needles, chlortetracycline during vector season, testing and culling in winter), we can clear the herd in a couple of years. (But) it’s always a good idea to test for anaplasmosis whenever purchasing cattle.” He added, “With the primary vector being biting insects, then control of flies and ticks is important. Tick control is difficult as most of our external parasite control products do not have a claim for tick control, and the ones that do would need to be applied on a regular basis through the summer. You can reduce some tick exposure by decreasing brush and keeping pastures grazed so that ticks do not have a habitat. Biting flies can be controlled, but they need to be applied regularly.” Citing a 2022 University of Georgia College of Veterinary Medicine report, Duggin said, “In the U.S., the cost of a clinical case of anaplasmosis is conservatively estimated at $400 per animal, according to their findings. That cost has likely increased since then. Working with a veterinarian to be proactive in prevention will be a great step forward in reducing mortalities and economic losses.”
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