Missouri researchers are taking a closer look at one of the state’s most common ticks as they work to protect the cattle industry from a costly livestock disease.
A team from the University of Missouri has completed a new study examining how the American dog tick may contribute to the spread of bovine anaplasmosis, a disease that attacks red blood cells in cattle. The illness can reduce weight gain, weaken animals, trigger abortions in pregnant cows, and in severe cases, lead to death.
The research comes as bovine anaplasmosis continues to be a growing concern for Missouri cattle producers. A previous University of Missouri study found that nearly half of the state’s cattle have been exposed to the disease, making it an ongoing economic challenge for an industry valued at roughly $4 billion.
To better understand the role of ticks, researchers collected more than 29,000 ticks from cattle pastures in five Missouri counties. About 1,500 of those specimens were identified as American dog ticks and were tested for the bacteria responsible for bovine anaplasmosis.
The results surprised researchers. Less than one percent of the male American dog ticks carried the disease causing bacteria, suggesting the infection may be spreading through additional routes that are not yet fully understood.
Researchers believe one possibility is that ticks move directly between cattle while animals gather closely together around shade, feed, or water instead of waiting on vegetation for a new host. That behavior could help explain why exposure rates remain high even though relatively few ticks tested positive.
The findings have been published in the Journal of Medical Entomology and will help guide future research into disease transmission and livestock health management.
The study also highlights the growing impact of Missouri’s changing weather patterns on tick populations. University of Missouri specialists say warmer winters, earlier springs, and extended periods of humidity are allowing ticks to survive and reproduce more successfully than in the past. Instead of being killed by prolonged cold, many ticks survive by sheltering beneath leaf litter, crop residue, or snow cover until temperatures rise.
Extension specialists encourage producers to remain vigilant during tick season. Keeping cattle and working dogs on veterinarian recommended tick control programs, regularly checking livestock for ticks, and reducing heavy vegetation around pastures can help lower the risk of exposure. People working outdoors should also wear protective clothing and check themselves for ticks after spending time in fields or wooded areas.
Researchers say continuing to understand how ticks spread disease will be critical to protecting Missouri cattle herds and reducing economic losses for producers across the state.