Is Canine Ehrlichiosis, a Tick-Borne Disease in Dogs, Increasing in Arkansas?
Research featured in latest issue of Discovery journal offers clues
By John Lovett – Oct. 2, 2025
FAYETTEVILLE, Ark. — Arkansas is still a state with high levels of canine ehrlichiosis, a tick-borne disease that impacts dogs, and the rate appears to be slightly higher than it was five years ago, according to a study published in the latest edition of the journal Discovery.
Discovery is the undergraduate research journal of the Dale Bumpers College of Agricultural, Food and Life Sciences at the University of Arkansas.
Eva Berryhill, an animal science honors graduate from Malvern, worked with faculty mentor Kelly Loftin, extension specialist and professor in the entomology and plant pathology department, to show the percentage of dogs testing positive for canine ehrlichiosis in the northern and southern reaches of the state to be from 22 to 23 percent in 2023 and 2024.
The incidence rate is about 3 percent higher than that found in a similar study conducted on dogs in Arkansas from 2013 to 2019. However, data from the more recent study indicated that while many dogs tested positive for ehrlichiosis, few were symptomatic. The disease can cause many symptoms, including fever, lethargy, anorexia and joint pain, to name a few.
Tests from one veterinary clinic showed that about 3 percent of the dogs tested for ehrlichiosis had symptoms of the disease in 2023, while there were no symptomatic dogs in 2024. Most of the dogs that were infected with canine ehrlichiosis were not on flea and tick prevention, the study noted. The disease is treated with an extended course of antibiotics, and treatment success depends on the stage of the disease at the time of treatment.
Of the nearly 500 ticks collected in the study, the majority were found to be Amblyomma americanum — better known as the lone star tick — a species known to carry an Ehrlichia bacteria species which can cause ehrlichiosis. Analysis was conducted on the ticks from both outdoor settings and veterinary clinics in Malvern and Fayetteville.
“Canine ehrlichiosis is one of the more common diseases that canines get from vectors such as ticks. It is more common in certain areas of the country than others,” the study noted. “In previous prevalence studies, it was noted that the number of dogs testing positive for the antibodies to the Ehrlichia bacteria has been increasing in some regions, specifically the southeast. Changes in climate, household income, and wildlife populations could explain this increase.”
Loftin, an extension entomologist for the University of Arkansas System Division of Agriculture and researcher with the Arkansas Agricultural Experiment Station, oversaw Berryhill’s work on the study. Emily McDermott, an assistant professor in the entomology and plant pathology department, and Jeremy Powell, a professor in the animal science department, also provided support and guidance in the study.
Beth Kegley, a professor of animal science, has been the Discovery journal’s faculty editor since 2019. Kegley said Berryhill’s study will inform decisions about future research, such as tests to determine which Ehrlichia species is infecting dogs, and veterinary recommendations for dogs in the state. Berryhill is pursuing her Doctor of Veterinary Medicine degree this fall at the Texas A&M College of Veterinary Medicine and Biomedical Sciences.
McDermott, Powell and Kegley are all faculty members with Bumpers College and the experiment station, the research arm of the Division of Agriculture.
The 2025 issue of Discovery includes seven additional articles on topics spanning animal, plant and human sciences.
The research and creative projects include:
- Expectations of parents towards pediatric care, with student author Brenan Cash from West Fork.
- Effects of genotypic variation and wilting speed on soybean germination and growth, with student author Adriana Peissel from Katy, Texas.
- Immune response in a scleroderma-prone chicken and implications for human health, with student author Katee Johnson from Mountainburg.
- Expectations about long-term care responsibilities between those participating in living-apart-together relationships, with student author Allison Martin from Tulsa, Oklahoma.
- Investigating different methods of weaning lambs and their effect on stress, with student author Emma Sutton from Poplar Bluff, Missouri.
- The effectiveness of a pheromone solution to mitigate stress in calves, with student author Elle Johnston from Sarasota, Florida.
- Occupational therapists’ perceptions on nature-based play, with student author Abbi Rosenow from Kenmore, Washington.
Jeff Edwards, dean of Bumpers College, congratulated the student researchers on completing their projects and thanked the faculty, mentors and editors who worked with them to make the recent issue of Discovery possible.
“We believe in creating opportunities for students,” Edwards said. “Opportunities to learn, to lead, and to launch careers that strengthen families, revitalize communities, and build a more prosperous Arkansas.”
Gail Halleck, managing editor of Discovery since 2010, said the deadline to enter a research project for submission to the next journal is May 6, 2026. Benefits for those who are published, Halleck noted, include sharing research in a citable publication, enhancing the value of a bachelor’s degree and developing skills needed to succeed in graduate school.
The faculty editorial board for the Discovery journal includes faculty from Bumpers College and the Division of Agriculture, including Matt Bertucci, assistant professor of horticulture; Eunjoo Cho, associate professor with the School for Human Environmental Sciences; Fred Dustan Clark, extension poultry health veterinarian and associate director of the Center of Excellence for Poultry Science; Ashley Dowling, professor of entomology and plant pathology; Don Johnson, University Professor of agricultural education, communications and technology; Michael Popp, professor of agricultural economics and agribusiness; Vibha Srivastava, professor of crop, soil and environmental sciences; and Ya-Jane Wang, professor of food science.
To learn more about the Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website. Follow us on 𝕏 at @ArkAgResearch, subscribe to the Food, Farms and Forests podcast and sign up for our monthly newsletter, the Arkansas Agricultural Research Report. To learn more about the Division of Agriculture, visit uada.edu. Follow us on 𝕏 at @AgInArk. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit uaex.uada.edu.
About the Division of Agriculture
The University of Arkansas System Division of Agriculture’s mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation’s historic land grant education system.
The Division of Agriculture is one of 20 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on three campuses.
Pursuant to 7 CFR § 15.3, the University of Arkansas System Division of Agriculture offers all its Extension and Research programs and services (including employment) without regard to race, color, sex, national origin, religion, age, disability, marital or veteran status, genetic information, sexual preference, pregnancy or any other legally protected status, and is an equal opportunity institution.
DISCOVERY — Eva Berryhill, right, an animal science honors graduate, is pictured on the cover of the 2025 Discovery journal with Sophie Mauldin, DVM, at Providence Veterinary Care in Malvern. Berryhill researched canine ehrlichiosis as part of her Bumpers College undergraduate honors thesis. (U of A System Division of Agriculture photo)
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