Guidelines for Evaluating Antiviral Products in Poultry Farms

Dr. Majed Hamed Al Saegh / poultry pathologist / Australia

13/ 9/ 2025

Introduction

Recently, poultry farmers have been increasingly offered products purportedly known as antivirals to combat avian diseases. Despite the promise of these treatments, it should be noted that only a very limited number of antivirals have been licensed for veterinary use (in some countries, only certain types of interferon are permitted). Many commercial products marketed as supplements or preventative treatments may not be supported by sufficient scientific evidence and may even contain illegally added pharmaceutical ingredients. For example, at least five commercial veterinary products were found in one study to contain the anti-influenza drug amantadine (in addition to two other products containing acyclovir). These products were registered as “food supplements” even though the antivirals were secretly added to them during the manufacturing process. Natureasia.com Therefore, it is essential to verify any product advertised as an antiviral before using it on a poultry farm, to avoid wasting money or exposing birds and people to unknown risks.

Key Questions Before Using a Product

1. Farmers should ask the following questions before using any product marketed as an antiviral to ensure its reliability and safety:
2. What is the name of the active ingredient? (Knowing the active chemical allows farmers to research its scientific information and verify its effectiveness and safety.)
3. Is it licensed for use in poultry? (It is important to ensure that the product has been approved by official veterinary authorities for use in birds. An unlicensed product may be illegal or has not undergone the necessary testing.)
4. Are there published, reliable trials in the field or on live birds? (Look for published studies or field trials that prove the product’s effectiveness in real-world situations. The presence of controlled trials in actual farms or on birds lends greater credibility to the product’s claims.)
5. Is there a risk of drug residues remaining in the meat or eggs? (It is important to know whether using the product will leave drug residues in poultry meat or eggs, which could render them unfit for human consumption without a sufficient withdrawal period. The presence of residues that do not meet standards may lead to health problems for the consumer and legal consequences for the farmer.)

6. Is its use prohibited by regulatory authorities (such as the FDA, EFSA, or WOAH)? (Some substances may be prohibited in the poultry sector by decision of global or local regulatory bodies. For example, the US Food and Drug Administration (FDA) has prohibited the use of human antivirals such as oseltamivir—commercially known as Tamiflu—in poultry to prevent the emergence of drug-resistant influenza viruses. It is important to check whether the product or its active ingredient is also prohibited by bodies such as the European Food Safety Authority (EFSA) or the World Organisation for Animal Health (WOAH).)

Warnings against indiscriminate use

The ill-advised use of antivirals in poultry farms can entail serious risks, including:

• Risk of drug resistance: Administering antivirals without veterinary controls or guidelines creates selection pressure on viruses, potentially resulting in resistant strains that are resistant to treatment. For example, in China, the irresponsible use of amantadine in chickens caused the development of a strain of influenza virus that was resistant to the drug, rendering it ineffective. natureasia.com International health organizations such as the World Health Organization (WHO), the Food and Agriculture Organization (FAO), and the World Food Programme (WFP) have warned that the use of human-grade influenza antivirals in birds could lead to the emergence of highly resistant strains of avian influenza (such as H5N1) (avma.org). This drug resistance not only harms the poultry industry but could also pose a risk to human health if resistant strains are transmitted to the poultry industry.

• Residue risk and legal and commercial implications: Any medication administered to poultry (meat or egg) may leave drug residues in animal products. The presence of drug residues at levels above legal limits renders these products unfit for human consumption and may lead to shipments being destroyed or rejected by regulatory authorities and importing markets (canr.msu.edu). Many countries have strict programs to monitor drug residues in meat and eggs (canr.msu.edu); If traces of prohibited or unauthorized substances are discovered, the farmer faces legal consequences (such as fines or product destruction), significant business losses, and damage to the farm’s reputation and consumer confidence. Commitment to the safe use of medicines and avoiding random handling protects the farmer from these problems.

Reliable Alternatives for Virus Control in Poultry

Fortunately, there are scientifically proven alternatives that can be relied upon to boost herd immunity and prevent viral diseases, without resorting to unproven treatments. These include:

1. Vaccination Programs Tailored to the Local Strain: Preventive immunization with appropriate vaccines is one of the most important pillars of protecting poultry from viral diseases. The vaccination program should be designed based on the viral strains prevalent locally to ensure effective acquired immunity. Properly designed and scheduled vaccines have proven their ability to reduce the incidence of serious diseases on poultry farms. For example, vaccination against Newcastle Disease or Avian Influenza with vaccine strains identical or closely related to the strain present in the area provides better protection for the flock than general vaccinations.

2. Enhancing Biosecurity on the Farm: Biosecurity is the first line of defense to prevent the introduction of any virus into poultry houses and its spread among them. This includes a set of strict practices and procedures that must be followed daily, such as restricting visitor access to the rearing house, ensuring that footwear and equipment are disinfected upon entry and exit, separating different batches or ages of birds, safely disposing of carcasses and waste, and maintaining clean water and feed. These measures drastically reduce the likelihood of disease entering the farm (woah.org). Studies have shown that strong adherence to biosecurity measures prevents the spread of pathogens on farms, reducing the need for antibiotics or other treatments later. Investing time and effort in improving biosecurity is a direct investment in flock health and farm profits.

3. Early Detection and Rapid Isolation of Illness: Daily monitoring of bird health allows for early detection of any signs of illness, which is essential to preventing disease outbreaks in the flock (aphis.usda.gov). Farmers should be aware of the symptoms of common viral diseases (such as lethargy, decreased feeding or production, abnormal respiratory or neurological secretions) and immediately isolate birds showing worrisome symptoms from the rest of the flock. Rapid isolation of suspected cases and imposing a form of quarantine on the affected area is a standard procedure in response plans for serious poultry disease outbreaks (avma.org). It is also recommended to notify a veterinarian or veterinary authorities when a viral epidemic is suspected. Prompt professional action (through laboratory diagnosis and measures such as culling infected birds or disinfecting the site) helps contain the disease before it spreads to neighboring farms. Early detection and prompt action can mean the difference between containing a disease to a limited area and a pandemic that causes significant losses to farmers in the region.

In Brief

There are no quick fixes for combating poultry viruses. Products promoted as a “super-viral” should be treated with skepticism and questioning. Adopting scientific preventative measures such as proper vaccination, biosecurity, and early monitoring is the surest way to protect the flock and maintain the health of poultry in the long term. Making decisions based on reliable information and veterinary advice saves farmers a lot of trouble and ensures safe and sustainable production.