From dairy farms to drug resistance, Ray Kaplan’s career-long fight against parasites the world keeps underestimating

In the late 1980s, Ray Kaplan ’83, DVM ’88 drove out to a goat farm in Pennsylvania where animals were dying from haemonchosis, a parasitic infection. The owner had been treating the herd with thiabendazole, but the drug was no longer working. 

Kaplan pulled out ivermectin, a new class of dewormer that had come on the market around the time he started veterinary school. The goats recovered almost immediately.

“I was able to be a hero,” Kaplan said. “Pull out the ivermectin and resolve it almost instantaneously.”

It was also, though he did not know it yet, his first encounter with anthelmintic resistance, or the inherited ability of parasitic worms to survive drug treatments — the problem he would spend the rest of his career trying to solve. For instance, ivermectin, once an anti-parasitic super-drug, now rarely works against haemonchosis. 

The Virginia-Maryland College of Veterinary Medicine has named Kaplan, a 1988 DVM graduate who also earned his bachelor’s degree at Virginia Tech, the recipient of its 2026 Lifetime Achievement Alumni Award. 

Kaplan is now senior associate dean at St. George’s University School of Veterinary Medicine in Grenada.

From dairy cows to parasites

Kaplan arrived at Virginia Tech at 17 as a dairy science major with a love of cows he had developed working on dairy farms in high school. 

Through the university’s Cooperative Education Program, he alternated quarters at a USDA research lab in Beltsville, Maryland, working on mammary physiology with cows. When the program’s funding was cut in the summer of 1981, the lab chief found him a temporary placement in another part of the complex: the Animal Parasitology Institute.

The detour stuck. When Kaplan entered the Virginia-Maryland College of Veterinary Medicine, he studied parasitology under Jurgen Hansen, who became an early influence. Kaplan completed a summer scholars research project with Hansen before graduating in 1988.

After graduation, he went into mixed-species private practice in Pennsylvania — the same practice where he would soon encounter those dying goats and the failing drugs. 

He enjoyed clinical work but decided it was not for him long-term. He left for a Ph.D. in veterinary parasitology at the University of Florida, completing it in 1995. His research focused on bovine liver flukes, a subject he had first delved into 10 years earlier at the USDA.

Jobs in the field were scarce. “You kind of had to wait for someone to retire or die,” Kaplan said. “And parasitologists don’t like to retire.” 

He did postdoctoral work at the University of Wisconsin, but with a young daughter, a newborn son, and a postdoc salary that could barely support his family, he needed something else. He spotted an advertisement for a position at the Walter Reed Army Institute of Research.

“I assumed it was a civilian position,” Kaplan said. “Turns out it was active duty.”

He nearly walked away, but conversations with classmates in the Veterinary Corps changed his mind. 

At Walter Reed, he became chief of the Parasite Biology Section, investigating malaria drug resistance. The work sharpened a question that had been forming since those Pennsylvania goat farms: Why do parasites keep outrunning the drugs meant to kill them?

Chasing a problem nobody wanted

When the University of Georgia hired Kaplan as an assistant professor in 1998, there was no existing large animal parasitology program to inherit. He built one from scratch, focusing on the problem nobody else was addressing: anthelmintic resistance.

Roger Pritchard, a world-renowned expert in anthelmintic resistance who became one of Kaplan’s mentors, advised him to focus on horse parasites specifically because no one else was studying drug resistance in that species. Kaplan took the advice and began conducting survey studies on farms across the southern and eastern United States. What he found alarmed him.

“It was so much worse than anyone had recognized it to be at that point in time,” Kaplan said. Drug resistance was not an isolated problem. It was highly prevalent, spreading across species, and largely invisible — because veterinarians were not following up after treatment to check whether the drugs had worked.

Over 23 years at Georgia, Kaplan built one of the field’s most influential research programs. His work moved across species as the resistance problem did — from horses and sheep into goats, cattle, camelids, and poultry — and eventually into companion animals when drug resistance emerged in canine heartworm and hookworm. 

His research on multiple-drug-resistant hookworms in dogs, conducted with one of his last Ph.D. students, revealed a widespread problem that had gone unrecognized.

Veterinarians would treat an infected dog and send it home. When the dog tested positive again a year later, they assumed that either the dog became reinfected or the larvae had simply leaked from the animal’s tissues — a known phenomenon in hookworm biology. If they had checked right after treatment, they would have seen that the dog’s infection was never cleared in the first place.

The underlying challenge, Kaplan said, is that parasites are nothing like the bacteria and viruses that veterinary medicine has learned to fight with vaccines.

“They’re complex eukaryotic animals share many of the same physiological pathways with mammals,” Kaplan said. “That makes developing new drugs extremely difficult, and it also has allowed the parasites to learn very intricate mechanisms of avoiding the host immune response. That’s why there are no parasite vaccines.” 

No new class of anthelmintic drug has reached the U.S. market since ivermectin arrived four decades ago. Resistance keeps spreading.

“It’s a problem that just keeps getting worse,” Kaplan said, “and the solutions aren’t keeping up.”

In 2020, Kaplan moved to St. George’s University in Grenada, where he had been visiting for years as a guest lecturer. Within months of arriving, the senior associate dean announced his retirement. Kaplan took the role and spent the past four years helping lead the veterinary school through a successful seven-year reaccreditation. He remains affiliated with the University of Georgia as professor emeritus.

When Kaplan learned that the veterinary college at Virginia Tech would honor him with its Lifetime Achievement Alumni Award, the recognition carried a weight that reached beyond professional accomplishment. His 40th wedding anniversary falls the day after the ceremony. He married his wife at War Memorial Chapel on the Virginia Tech campus while in veterinary school, with classmates in attendance.

“At 17, I walked onto the Virginia Tech campus for the first time,” Kaplan said. “That experience defined my identity and career.”

“To be recognized by my alma mater and my peers is very meaningful to me.”