Whenever farmers get sick, have a fever or sprain an ankle, there are countless options of aspirin or ibuprofen to take for pain relief. However, when a dairy farmer’s animal experiences pain through disease or injury, the options are extremely limited.
Painkillers or analgesics are becoming more commonly accepted by producers for their food-producing animals. Administering nonsteroidal anti-inflammatory drugs (NSAID), such as flunixin, aspirin or meloxicam, to an animal is similar to giving a person acetaminophen or ibuprofen for pain relief.
Unfortunately, right now there are currently no NSAIDs specifically approved by the FDA for pain relief in lactating dairy cows. However, the Animal Medicinal Drug Use Clarification Act of 1994 (AMDUCA) permits veterinarians to prescribe extra-label uses of certain approved animal drugs and approved human drugs for animals under certain conditions.
NSAIDs in today’s market
One of the most common NSAIDs used in an extra-label manner is flunixin, which is primarily sold as Banamine, says Hans Coetzee, Kansas State University professor and head of the department of anatomy and physiology in the College of Veterinary Medicine.
“Banamine injection is a classic example of a NSAID effective at reducing pain but only approved for reducing fever and inflammation in lactating dairy cattle,” Coetzee says. “However, the current challenge with Banamine injection is: It must be administered intravenously. If Banamine is injected into the muscle, there are serious issues with tissue and milk residues, which is a significant area of concern for the entire dairy industry.”
Coetzee says the most common approved use of NSAIDs in dairy production systems is to treat fever and inflammation.
“Acute mastitis, where the cow has a swollen udder and high fever, is an example where we would use NSAIDs to reduce the fever and swelling in the udder,” Coetzee says. “Oftentimes, NSAIDs will also make the cow feel more comfortable by relieving the pain caused by the mastitis, even though the drug is not specifically approved for this purpose.”
Another condition where NSAIDs are approved to reduce fever is pneumonia, which is also called bovine respiratory disease.
Besides Banamine, producers may also be familiar with using aspirin boluses to treat pain and fever in dairy cows. However, unlike Banamine injection, aspirin has never been approved by the FDA for any indication in cattle, including pain relief, and are thus used in an extra-label manner.
“One of the challenges with oral aspirin is: It is very short-acting and therefore does not provide lasting relief to the animal. Furthermore, most of the drug, about 80 percent, is not absorbed from the gut, and only about 20 percent of the drug is actually available to have an effect in the animal,” Coetzee says. “Therefore, it is important for dairymen to recognize if they continue to use oral aspirin, it firstly is not approved and, secondly, most of the drug is lost from the animal and is therefore not very effective for improving the health and welfare of the cow.”
Although there are no NSAIDs approved for pain relief in lactating dairy cows or calves, one has recently been approved for use in dairy heifers for relieving pain associated with foot rot and fever associated with bovine respiratory disease.
In January, Merck Animal Health introduced Banamine Transdermal as the first and only FDA-approved product for pain control in food-producing animals. Applied as a pour-on, the product is easy to administer for pain and fever management.
This new approach aligns with industry efforts to continuously improve animal care. The pour-on requires less handling and offers needle-free administration, which results in less stress on the animal.
“Currently, there is no milk withholding information available for Banamine Transdermal,” Coetzee says. “But when this is addressed, I believe this drug will become widely used on dairy production systems. Not only is it effective but also convenient because producers will simply apply it as a pour-on to the skin along the back of the animal and will not have to inject it into a vein.”
Challenges to approving NSAIDs
Anything worthwhile takes time and effort. Getting NSAIDs FDA-approved is a time-consuming process. It involves meeting government standards, developing a formulation, getting the right dose and proving intended label claims. One of the primary challenges pharmaceutical companies face to get a drug approved and to obtain a pain relief label is: They have to validate a method of pain assessment in the animal.
“One method we have found to be very effective is the use of a pressure-sensitive mat. We can walk a lame animal across the mat and, based on the stride length and the force and contact area applied to each of the four feet, we can assess the gait and measure changes in response to the pain relief drug,” Coetzee says. “This is the tool used to get Banamine Transdermal approved with the label claim for reducing pain associated with foot rot lameness.”
A second challenge Coetzee sees is, of course, dealing with milk residue concerns. It is necessary for there to be reliable data to provide dairymen estimates of how long they should wait after treatment before milk will be acceptable for human consumption.
“I believe there are a number of areas where NSAIDs could benefit dairy production systems and the dairy industry in the future. The most obvious is to provide pain relief and pain management in order to address animal welfare concerns in livestock production systems,” Coetzee says. “I also believe there are unrealized economic benefits associated with the use of NSAIDs based on research we conducted with Dr. Barry Bradford’s group at Kansas State University.”
Bradford and his colleagues found administering an NSAID after calving increased milk production by an average of 1,000 pounds per cow over the course of a lactation.
Another challenge Coetzee mentioned was the need for pharmaceutical companies to invest in obtaining additional label claims and, especially, milk withhold period recommendations for NSAIDs in dairy cows.
“I believe in large part this will be driven by producer demand. If producers demand more of these approved drugs to address animal welfare concerns and to realize the production benefits these compounds may provide, this will drive the market by demonstrating to companies there is value in investing in seeking approvals for these drugs,” Coetzee says.
The other responsibility lies with the FDA to continue to provide the necessary framework and protocol guidance the pharmaceutical industry needs to enable them to get NSAIDs approved for use in livestock, Coetzee says. “With the approval of Banamine Transdermal, the FDA showed they will work with the pharmaceutical industry to develop realistic and attainable regulatory expectations to address the need for pain relief drugs for use in livestock.”
Researchers have made significant advances in developing validated pain models that can be used to get NSAIDs approved and identifying potential drugs that are safe and effective for use in animals. However, at the end of the day, it takes a pharmaceutical company willing to invest in a research program to bring these drugs to market.
“Our livestock producers are connected with the animals they take care of every day and have a very strong bond with those animals. They always strive to do the best they can for the animals in their care,” Coetzee says.
“The absence of drugs approved for pain relief is obviously a significant impediment to producers to be able to provide the best quality of care to their animals. So I believe this is a very urgent and important need, that this need must be addressed.” 
ILLUSTRATION: Illustration by Corey Lewis.
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Audrey Schmitz
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- Progressive Dairyman
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