The use of nanosilver products against foot-and-mouth disease (FMD) in South Africa should be approached with caution, as these products are not registered as livestock medicines in the country but as feed supplements.
By Vida Booysen, senior journalist at African Farming and Landbouweekblad
From discussions on social media, it is clear that desperate and discouraged farmers caught up in the FMD crisis are resorting to any possible measure to try ans contain the virus. One such measure is the use of products containing nanoparticles of silver.
Videos circulating online claim nanosilver kills the virus and can even treat animals that already have FMD. It is further alleged that the product has been used on thousands of cattle in South Africa that were already infected. According to these claims, affected animals recover faster and the product prevents the virus from spreading through the herd, thereby supposedly reducing farmers’ losses.
The problem is not so much what is being said, but what is not being said, warns Dr Dave Midgley, head of the Ruminant Veterinary Association of South Africa (RuVASA).
“Farmers are under the impression that the nanosilver products are registered, and indeed they are registered. But not as medicine. These products are registered in terms of Act 36 of 1947 as animal feed supplements. It is misleading to present them as medicine.”
Scientific research shows that nanosilver, when used as a feed supplement, may have certain benefits. The issue is therefore not nanosilver itself, but misleading marketing that converts feed-related benefits into untested medicinal claims.
Also read: FMD | A farmer shares what helped his animals recover
What does Act 36 of 1947 say about S and V registrations?
Act 36 of 1947 makes a critical distinction between two types of products that may be given to animals. According to the regulations of the Act, veterinary medicines, identified by S registration numbers, must be supported by scientific evidence of safety, quality and efficacy. These products may make specific therapeutic claims, such as the ability to treat or prevent disease, but only once biological efficacy under South African conditions has been proven.
In contrast, feed supplements, where the registration number is preceded by the letter V, are defined as products “used with other feeds to improve the nutritional balance or performance of the whole feed”. The Act clearly states these products “may not claim to treat or cure disease”. Any advertisement or label that makes false or misleading claims is prohibited.
The Act further requires that all advertisements must be “scientifically verifiable” and that the registrar may demand supporting evidence. Any reference to active ingredients, instructions for use, claims or registration details must be consistent with what has been approved on the product label.
Midgley explains that any product registered under an S-registration as a veterinary medicine for use against FMD must first undergo scientific, controlled trials in which the product is tested on livestock themselves. Laboratory tests alone are not sufficient, even if they demonstrate that the product can kill the FMD virus in a test tube.
“The FMD-affected herd used in the trial must be divided in half to include a control group. To determine whether nanosilver works, one half may only receive the product being tested – no painkillers or other drugs are allowed. The other half, which serves as the control group, receives no treatment at all, not even nanosilver. Do you really want to start running trials in the heat of an outbreak to try to prove that something works?”
Also read: RuVASA backs FMD strategy, but urges more consultation
Use at your own risk
Dr Johan van Rooyen of Steynsburg, another veterinarian who spoke to African Farming, also points out that there is no published research proving the product’s effectiveness or confirming that its safety has been tested in animals themselves.
“I’m not arguing that it may not work, and I’m very happy if it does work for some people, but a veterinarian cannot recommend a product without sufficient scientific support. Farmers who use it do so at their own risk.”
Midgley advises farmers to consult their own veterinarians before using any nanosilver products against FMD. “RuVASA cannot comment on a product that has not been tested in controlled, scientific trials.”
Van Rooyen emphasises that FMD will only be controlled by adhering to strict disease-control measures such as quarantine, movement restrictions and rigorous biosecurity.
“We take our eye off the ball when we start experimenting with all sorts of concoctions. If you tell a farmer there is a remedy that might work, it almost gives him an excuse not to maintain strict quarantine. I’m not going to make that recommendation. If people want to use nanosilver, it is at their own risk.”
Also read: ActionSA questions credibility of FMD vaccination strategy
