In October 2024, veterinarians across the country received the following letter from the Food and Drug Administration (FDA):
Dear Veterinarian:
The U.S. Food and Drug Administration understands that veterinarians and dairy farmers may be treating lactating dairy cattle for pyrexia and pain with aspirin and wants to clarify that there are no FDA-approved aspirin products for use in cattle. The extra-label use of unapproved drugs in food-producing species is prohibited.
There are FDA-approved products for controlling pyrexia and pain in lactating dairy cattle that are safe, effective, and have established milk and meat withdrawal periods. All FDA-approved animal products are required to carry one of the following statements on the label:
“Approved by FDA under NADA # XXX-XXX” (for brand name animal drugs), or
“Approved by FDA under ANADA # XXX-XXX” (for generic animal drugs).
Under the Animal Medicinal Drug Use Clarification Act (also known as AMDUCA), veterinarians may use an FDA-approved human or animal drug in food-producing species under specific conditions. There is one FDA-approved human aspirin product (Vazalore) that is currently marketed. Although other human aspirin products are marketed under an over-the-counter monograph, that monograph is not an approval and, therefore, these products cannot be used in an extra-label manner. Given the impracticality of dosing cattle with a sufficient amount of the approved human product, the FDA understands that veterinarians and dairy farmers may instead be using unapproved aspirin products that are not legally marketed. The extra-label use of unapproved drug products in food-producing species is prohibited.
What Does This Mean?
Due to this new classification, it and aspirin derivatives cannot be used in food producing animals.
The back story to this is previously, aspirin and the salicylates were considered low risk of problems contaminating the US food supply. As Highly Pathogenic Avian Influenza (HPAI) spread rapidly through the US dairy herd in spring and summer 2024, traces of aspirin were showing up in the milk supply. Due to this, the FDA no longer considered aspirin and other derivatives “low risk” and now consider them to fall under their purview and law called AMDUCA.
This will require manufacturers to file for a NADA – this process generally is not fast – likely ~2-3 years with animal trials to study the elimination of the compounds from various tissues from meat producing animals. The cost associated with acquiring an NADA is likely between $500,000 and $1,000,000. It remains to be seen whether a manufacturer will spend those resources to bring these products back to market. If they do, the cost will likely increase due to the additional costs absorbed to acquire a valid NADA.
Options for producers are quite limited. Injectible anti-inflammatories such as Flunixin meglumine and dexamethasone are still readily available. Mass treatment options – something to put in the medicator – is limited to a prescription product called Meloxicam. This product does work quite well as an antipyretic, but is more costly than aspirin. Work with your veterinarian to understand dose, withdrawal, and cost.
Article by Cameron Schmitt, DVM
The Stuart, Iowa, native is a second-generation large animal veterinarian and earned his DVM and MS from Iowa State University. He joined Pipestone in 2002 and now practices and leads the vet team as the Executive Vice President of Veterinary Services.
