Neglected Risks of Veterinary Drug Use in Livestock: A Call for One Health

14 Nov, 2024

By: Angela R. Schug, PhD, Advisor and Dr. Sivaraman Balaji, Advisor- Human Health, One Health and Agroecology Project

Livestock plays an integral role in traditional farming agroecosystems in India, being essential to the livelihoods of small-scale farmers. It serves as a source of income, fertiliser, and food. While drugs such as antibiotics and antiparasitics are essential to livestock health and welfare, their use must be approached with caution. Alongside their benefits, there is a largely neglected concern: the human health and environmental risks that arise when these drugs are used carelessly.

Addressing these risks requires a One Health approach, recognising the interconnectedness of human, animal and environmental health. Incorporating agroecological principles, which emphasise sustainable food production in harmony with nature, further supports a balanced approach. Together, these frameworks foster a world with safe, nutritious food and a healthy environment. This call for action is reflected in the newly adopted global action plan on Biodiversity and Health at the 2024 United Nations Biodiversity Conference of the Parties (COP16) to the UN Convention on Biological Diversity (CBD) held in Cali, Colombia. By taking a One Health approach, this initiative aims to tackle health issues linked to biodiversity loss, curb the spread of zoonotic diseases, prevent non-communicable diseases, and promote sustainable ecosystems.

In line with these recent global efforts, there has been increasing attention to veterinary drug residues released into the environment, as they can disrupt ecosystems, endanger biodiversity and reduce soil fertility. They can negatively impact various organisms, such as dung fauna, pollinators and aquatic animals, and can impair the nutrient cycle and soil health. Despite growing awareness, much remains unknown about the long-term environmental impacts of veterinary drugs.

In addition, residues can accumulate in plants, circulate in the food and feed chain. In terms of food safety and human health, drug residues in animal products such as milk, eggs and meat are particularly problematic. Therefore, when using veterinary drugs in food-producing animals, special safeguards must be considered, such as a withdrawal period between the treatment of livestock and the use of products of these animals as food.

The Case of Diclofenac and the Indian Vulture Crisis

One of the most alarming examples of the impact of veterinary drugs on ecosystems is the near extinction of vultures in India. Diclofenac, a common pain-relieving drug used in livestock, caused widespread renal failure in vultures that feed on the carcasses of treated animals, leading to a dramatic population decline. However, this did not only affect the vultures – the near extinction of vultures led to widespread disruption of ecosystems. Other scavengers, such as stray dogs, increased in numbers, leading to higher rabies rates, and there was even evidence of increased death rates in humans in regions where vultures were almost extinct.¹ This case illustrates the broader far-reaching consequences of environmental contamination.

The Overlooked Dangers of Antiparasitic Drugs to Biodiversity and Health

Beyond the well-known case of diclofenac, other veterinary drugs - like antiparasitics - can also have unintended harmful effects on health and biodiversity. For example, Albendazole, a common antiparasitic in livestock, can disrupt ecosystems if drug residues enter the environment through animal waste. Incorrect use may also lead to drug-resistant parasites, making treatments less effective.

But the drug may also enter the food chain: A study conducted in the Sagar region of Madhya Pradesh state found nearly half of the food samples contaminated with antiparasitics like albendazole, at concentrations above international safety limits.² This may cause health risks for consumers and highlights the pressing need for stricter monitoring and regulation of veterinary drugs in livestock used for food production.

In addition, non-medical practices – such as different grazing practices – can also help reducing the worm load sustainably. Thereby, farmers can take care of the health of their herds and, at the same time, avoid costs for antiparasitic drugs and residues in food and environment.

The One Health and Agroecology Project

In Madhya Pradesh, the One Health and Agroecology Project supports farmers, veterinarians and decision makers from the animal husbandry, human health and environmental sectors to use animal drugs, especially the antiparasitic Albendazole, more judiciously, in order to reduce contamination of the environment and food stuff. This includes activities such as collecting, documenting, and sharing best practices that help local communities adopt more resilient and environmentally responsible livestock management practices. Women, who are at the heart of livestock care and food safety, play a central role in these efforts.

¹Indian vultures: Decline of scavenger birds caused 500,000 human deaths. Accessed November 5^th, 2024

²Pawar, R.-P. et al. (2021). Determination of albendazole and ivermectin residues in cattle and poultry-derived samples from India by micellar liquid chromatography. https://doi.org/10.1016/j.jfca.2021.104111

Veterinary drug residues released into the environment (for example via manure) can reduce soil fertility, as they impact various non-target organisms, such as dung fauna, pollinators and aquatic animals. © GIZ

In rural India, women are at the heart of livestock care and food safety, making them essential partners to establish more sustainable practices. They are often the first to notice and respond when animals get sick, taking on much of the responsibility for their care. Through commitment to sustainable methods, women can help create healthier farming systems that benefit families, animals, and the environment alike. © GIZ