Estimates from the U.S. Centers for Disease Control and Prevention (CDC) indicate the number of diagnosed cases of Lyme disease in the United States is about 10 times that of cases reported to the CDC through routine surveillance. Lyme disease is the most commonly reported tick-borne illness in the United States, with about 30,000 cases reported each year. The CDC estimates total annual diagnosed cases at around 300,000.
According to the CDC report, most reported Lyme disease cases are concentrated in the Northeast and upper Midwest, with 96 percent of cases in 13 states. Lyme disease is caused by the bacterium Borrelia burgdorferi and is transmitted to humans through the bite of infected blacklegged ticks. Typical symptoms include fever, headache, fatigue, and a characteristic skin rash called erythema migrans. If left untreated, infection can spread to joints, the heart, and the nervous system.
According to the USDA’s Agricultural Research Service, antibodies to B. burgdorferi have been demonstrated in cattle in Europe, Australia, the UK and the United States. Spirochetes have been detected from the blood and urine of cows in Wisconsin. At the present time, there is no set pattern of symptoms, diagnosis or treatment of the disease in cattle, according to ARS. Typically in the acute stage of the disease, cattle may develop fever, stiffness and swollen joints, lameness, and their milk production decreases. Chronic weight loss, laminitis, and abortion have also been reported. A rash may occur at the site of the tick bite in some cases, but may be difficult to see, if it occurs at all.
Unfortunately, the clinical signs of Lyme disease are very similar to other diseases common in cattle and the symptoms vary greatly among cows. The ARS notes cross-reactivity to other organisms similar to B. burgdorferi may lead to false positive results in serological tests currently in use. As in humans, an accurate diagnosis must include a history of potential exposure to the vector tick (Ixodes scapularis), appropriate clinical signs, elevated antibody titers to specific borrelial antigens, and a positive response to antibiotic treatment. Read more about Lyme disease in cattle from ARS.
Farmers, ranchers and veterinarians who work in the outdoors and around animals that could carry ticks should be aware of the risk of exposure.
The CDC recommends people take these steps to help prevent Lyme disease and other tickborne diseases:
- Wear repellent
- Check for ticks daily
- Shower soon after being outdoors
- Call your doctor if you get a fever or rash