Saving the Herds of Lapland: How an Antiparasitic Drug Helped Preserve Reindeer, Livelihoods, and Culture

In the early 1970s, reindeer herds across Lapland were in crisis. Parasitic infections were decimating calves, with losses in some herds reaching as high as sixty percent. For the indigenous Sami people, whose lives, livelihoods, and cultural identity are deeply intertwined with reindeer, these losses threatened more than income; they threatened a way of life that had endured for millennia. A veterinary breakthrough changed that trajectory when the antiparasitic drug thiabendazole, branded THIBENZOLE, was adapted for reindeer and, through carefully organized trials and field treatments, helped restore herd health, strengthen local economies, and support Sami cultural continuity.

Reindeer are central to Sami life. They provide meat and milk, hides used for tents and clothing, and draft power for sleds, essential resources for both subsistence and commerce. Beyond material needs, Sami worldviews emphasize deep spiritual and cultural bonds with reindeer; protecting the animals is therefore inseparable from protecting identity and tradition. Economically, the high mortality in young animals reduced herd productivity, lowered incomes for herders, and threatened the sustainability of reindeer pastoralism across northern Norway, Sweden, Finland, and Russia’s Kola Peninsula.

The scientific basis of the solution lay in addressing trichinosis, a parasitic disease caused by roundworms of the genus Trichinella. In the 1960s, researchers including William C. Campbell investigated compounds active against Trichinella and developed thiabendazole. Early laboratory work showed that thiabendazole could kill the parasite in mice, and by 1961 the compound had been trademarked and identified as the first drug known to kill trichinella. Over the following decade, the compound was adapted for use across a range of species, including cattle, horses, pigs, and reindeer.

Transitioning from laboratory discovery to field application required determination and careful coordination. In 1971, MSD Animal Health researchers partnered with Norway’s State Veterinary Laboratories in Harstad to mount a government-supported trial focused in Finnmark province, where Sami communities and reindeer herding are concentrated. The fieldwork demanded extraordinary logistics. Teams worked in 24-hour summer daylight to gather, earmark, weigh, and treat calves across a concentrated three-week period. Later phases required tracking migrating herds across snowy landscapes by snowmobile and sled, treating animals in complete darkness and bitter cold. Despite those harsh conditions, researchers completed the multi-year program through 1973.

The results were meaningful and measurable. Treated reindeer gained weight and appeared healthier than untreated animals, indicating that eliminating the parasite improved growth and overall fitness. Market value rose dramatically for treated animals; prices for treated reindeer were more than five times those for untreated ones, increasing income for herders and strengthening the local economy. Perhaps most importantly, by reducing herd losses and improving animal health, the program helped safeguard Sami livelihoods and the cultural practices tied to reindeer pastoralism.

The Lapland reindeer story illustrates how targeted scientific research can translate into practical solutions across diverse ecosystems. The adaptation of thiabendazole from a laboratory discovery into a multi-species veterinary tool serves as a model of veterinary innovation. The work on antiparasitic agents in veterinary contexts also contributed to wider advances in parasitology and drug development, informing later breakthroughs with major public health consequences. Equally notable was the manner of implementation: coordinated efforts with local institutions and attention to community needs demonstrated how scientific interventions can support indigenous peoples while respecting traditional knowledge and practices.

This small story has a big lesson: animal health is tightly bound to human well-being, economies, and cultures, especially where a single species plays a central role. Thoughtful science, patient fieldwork, and collaboration with local partners preserved herds and protected a way of life that matters deeply to the Sami.