Dr. Gately has been a mentor to me in the large animal field service, and Dr. Gatlin significantly contributed to my continued interest in public health. Both played such a big role in my education while I was deciding what career path I wanted to take. I feel very fulfilled about the work I was able to do with Dr. Gatlin and Dr. Gately. This research project was the highlight of my time at Tufts [Cummings School].
Dr. Eleanor Kharasch, V25, MG25 (M.P.H.), Publishes Research in Collaboration Between TVFS and MPH Program
Research offers insights into treatment for small ruminants, addressing industry-wide health issue of parasite resistance
Two summers ago, Dr. Eleanor Kharasch, V25, MG25 (M.P.H.), put 3,000 miles on her car visiting farms across three states for her research into the efficacy of a first-line treatment for parasites in goats and sheep. A student in the dual degree D.V.M./Master of Public Health (M.P.H.) program at Cummings School of Veterinary Medicine at Tufts University, she conducted the research project through the Summer Research Program, funded by the Foundation for Food & Agriculture Research (FFAR) as a Veterinary Research Fellow and Tufts Jonathan M. Tisch College of Civic Life. Her paper is featured in the August 2025 issue of Veterinary Parasitology: Regional Studies and Reports.
Kharasch is the lead author of the study, "Efficacy of fenbendazole in small ruminants on Southern New England farms," conducted under the interdisciplinary mentorship of Dr. Rachael Gately, clinician with Tufts Veterinary Field Service (TVFS) and associate clinical professor in the Department of Ambulatory Medicine and Theriogenology, and Dr. Meera Gatlin, V16, VG16, track leader of the M.P.H. program and assistant teaching professor in the Department of Infectious Disease and Global Health at Cummings School.
"Food and large animal medicine are an essential part of understanding veterinary public health; the clinicians at TVFS address population health every day, not to mention topics like ensuring food safety and combating antimicrobial resistance," says Gatlin. "As a D.V.M./MPH student myself, I did my research with TVFS, so I am excited to support my students similarly and to continue this collaboration."
D.V.M./MPH students complete a capstone project addressing an issue within animal population health and its potential impact on human health, utilizing their training in epidemiology, biostatistics, and research methods.
"The Summer Research Program is a perfect opportunity to meet these requirements," says Gatlin. "When you add in faculty collaborations like with TVFS and administrative support towards publication, it is immensely rewarding for my students to add research as an additional skillset. As they apply their public health training in practice, they can feel empowered to read about research findings, conduct research themselves, or consider a career in government or academia where these skills are equally useful. It adds a valuable dimension to clinical practice."
The idea for the research project came to Kharasch during a parasitology lecture Gately delivered on the challenges producers and veterinarians face when managing sheep and goats afflicted with parasites, which can be fatal. The impetus behind her work was to help producers by determining the efficacy of the common dewormer fenbendazole in treating parasitism in small ruminants. TVFS producers had reported mixed results with this medication.
"Many parasite populations are resistant to numerous dewormers, making treatment and the ability to resolve parasites difficult, to the point where blood transfusions may be indicated," says Kharasch. "People know anecdotally that certain dewormers may not be working in their herds. We wanted to gather data specific to our region to help guide clinical decision-making and make tailored recommendations to producers."
Kharasch was awarded FFAR funding to expand the scope of her project. "I sought out research funding because I wanted a large enough sample size to provide meaningful data for producers and ultimately a published manuscript. Funding helped make my sample size as large as possible, with the ability to service TVFS sheep and goat producers."
For the study, 27 farms in Massachusetts, Connecticut, and Rhode Island were recruited. The farms participated in a survey to gather perspectives on parasite prevention, resistance, and management strategies. Thirty sheep and 80 goats across 19 of the farms had eligible animals for the study.
A reliable diagnostic tool in field medicine to assess for parasites is fecal egg counts. Initial samples were collected and analyzed, and animals were individually weighed and administered fenbendazole. Kharasch returned to each farm 10 to 14 days later to collect and analyze a second set of samples after treatment.
Dewormer is considered efficacious if fecal egg counts are reduced by 90 percent after treatment. Kharasch found egg counts within the study population had an average of 41 percent reduction after treatment, demonstrating that fenbendazole is not effective in treating strongyle parasites in sheep and goats. The drug displayed a 90 percent reduction in fecal egg count in only 14 of 110 small ruminants in the study. Her findings also pointed to significant resistance to fenbendazole.
"It is widely accepted by many clients of TVFS that a lot of our small ruminants have some level of resistance to fenbendazole. Eleanor's research allowed us to finally quantify that resistance and really apply that information," says Gately.
"During sampling, we knew we were getting really valuable data," says Kharasch. "This helped us inform producers with direct evidence that we can no longer deworm our way out of managing parasites in our sheep and goats. A portion of parasites exposed to treatment that survive subsequently become a resistant population that continues to cause clinical disease and blood loss in those animals and become infective larvae on pasture, exposing other animals in the herd. We need to implement strategies to prevent persistence of anthelmintic resistance by monitoring clinical signs in conjunction with management tools such as fecal egg counts, pasture management, and rotational grazing."
Larvae hatch and survive for long periods in warm, humid weather, while they are less likely to survive in hot, dry areas. Leaving grazed pasture unused for periods of time during hot, dry weather can decrease the load of infective larvae. Pasture grass height also plays a role in the exposure of animals to infective larvae.
"Minimizing the use of dewormers while implementing parasite management tools is paramount," says Kharasch. "In the past, dewormers were used in all animals regardless of their parasite status or presence of clinical disease. Changing our decision-making process of when to use dewormers can help slow down the progression of anthelmintic resistance in our animals."
Co-authors of the study, Gately and Gatlin, were invaluable resources to Kharasch. She also appreciated working so closely with TVFS clients.
"This project highlighted a great opportunity for both our students and our clients," says Gately. "We had a tremendous response from our clients as they were willing to participate and excited to work with Eleanor collecting the data. Similarly, Eleanor found them to be welcoming and compliant with the project design. We all worked together very well to improve our understanding of managing parasitism in sheep and goats."
After graduating from the dual degree program this past May, Kharasch began a large animal internship in the field service in the Department of Veterinary Preventive Medicine at The Ohio State University.
"I love large animal ambulatory medicine and being at farms to help clients meet their goals, whether it's a commercial business, hobby farming, or companion livestock," says Kharasch. "Dairy production in particular really interests me through its intersection with public health—food safety, infectious disease, and contributing to a farm's business—and makes large animal medicine so much fun."
Kharasch hopes to conduct more field research in the future to benefit both clients and fellow large animal vets.
“Dr. Gately has been a mentor to me in the large animal field service, and Dr. Gatlin significantly contributed to my continued interest in public health. Both played such a big role in my education while I was deciding what career path I wanted to take,” says Kharasch. “I feel very fulfilled about the work I was able to do with Dr. Gatlin and Dr. Gately. This research project was the highlight of my time at Tufts [Cummings School].”