A new topical drug promising pain relief from a specific ailment affecting cattle is now available in Canada.
Banamine transdermal, a non-steroidal anti-inflammatory drug (NSAID) produced by Merck Animal Health, was released at the end of January. This pour-on product, with flunixin meglumine as the active ingredient, is used to reduce fever related to bovine respiratory disease (BRD). However, it’s the drug’s proven ability to relieve pain related to foot rot that is stirring up interest now that has been included on its label.
“Initially, it came out that it was an anti-pyretic,” says Roy Lewis, a technical services veterinarian with Merck and frequent Canadian Cattlemen contributor. “The biggest application for that in the cattle world would be a calf in a feedlot with pneumonia, let’s say. It’s going to be given an antibiotic of some sort, and then this drug would help pull the fever down, and so that was on the label initially.”
Lewis explains that most pharmaceutical companies that produce an anti-inflammatory drug are now focusing on specific ailments or procedures that cause pain. “That’s what they want to get on the label so that people see that they can use it for that.” In the case of banamine transdermal, Merck used foot rot as a model for lameness.
Merck chose to focus on lameness because it is an issue that affects all types of operations, and it was simple to measure the drug’s effectiveness, says Lewis. For example, for a product to be approved by the United States Food and Drug Administration (FDA), the drug company has to prove that it works. When it comes to proving that an animal’s pain has been lowered, pain needs to be measured in a simple way. As Merck was able to do this, banamine transdermal was approved by the FDA.
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This was achieved by using pressure plates to measure how much weight an animal puts on a specific foot as they walk. After walking lame cattle over a pressure mat to record this and other metrics, the cows were given the drug and then walked over the same mat six hours later. Based on this research, Merck found that the treatment decreased the pain in these animals by measuring the amount of pressure they put on the affected foot.
“It’s pretty easy to measure,” says Lewis, who explains that pain resulting from other ailments and procedures, such as castration, is often harder for researchers to quantify. “We know it’s painful and we know scientifically these drugs should work. Now we just have to prove it.”
While there are a number of different banamine products currently available for cattle, this specific treatment, a translucent red liquid, is applied along an animal’s back from withers to tailhead. It’s advised to apply this to dry, undamaged skin, not rubbing the product into the animal’s skin or hair. Producers need to ensure the animal doesn’t get wet for around six hours, according to the label, though Lewis suggests this length of time may be unnecessary, as it starts to absorb in about 15 minutes.
The drug was developed as a topical application for ease of administration. “As innocuous as it might be to give them a needle, you have to catch them in a chute or have them restrained, and it does in itself create a little bit of pain,” he says. You can apply it easily in an alley or by walking up to the animal if it is quiet enough.
Banamine transdermal comes in a plastic bottle with a graduated dosing chamber. The recommended dose is one ml per 15 kilograms, which Lewis says is a fairly low dosage. “It’s absorbed pretty quick and reaches maximum levels in the body in about two hours.”
The withdrawal time for slaughter is 13 days after the last treatment. As no milk withdrawal has been established, the drug is not yet approved for lactating dairy females.
The label warns that the drug shouldn’t be used on breeding sires “as the reproductive safety has not been evaluated.” Lewis confirms that this caution is due to the fact that there hasn’t been research into this particular area, so the implications are not yet known. “That’s where veterinarians have to use what we call ‘extra-label use’ and use our own best judgment,” he says. “If they know that this bull is lame and it should have this, in my eyes I don’t see any issue with it.”
The label also warns that NSAIDs may have the potential to delay calving, so it is not recommended for use within 48 hours of an expected calving date. As well, administering the drug immediately after calving may interfere with uterine involution and expulsion of foetal membranes resulting in retained placentae. This particular caution is related to the original injectable form of banamine, and Lewis confirms that it is a legitimate concern to consider when choosing a fever or pain reducer. “There is a little bit of higher incidence of retained placentas if it’s used,” he says.
The adverse reactions listed on the label include “transient swelling, erythema, dandruff, broken (or) brittle hair, hair thinning, alopecia or thickening of the skin… at the application site,” which may be due to an overdose.
The label advises that producers wear protective gloves and safety glasses when applying the drug. Lewis notes that while this may make producers worry that it’s particularly dangerous, earlier pour-on products were introduced before more recent safety regulations, and wearing safety glasses and gloves is always a good precaution when using topical treatments.
Banamine transdermal has a low freezing rate and a high flammability rate. The latter makes it safe to use at brandings, as opposed to pour-on products that contain rubbing alcohol. “In fact, I tried to set it on fire and I couldn’t,” says Lewis.
Lewis anticipates that Merck and other drug companies will be looking into new label applications for pain relievers like banamine transdermal. “Following the Beef Code of Practice and what the public is dictating, more and more pain killers are being used. So this drug and probably the other ones that are out there for pain, the companies will be researching more applications for it, like giving it at a hard calving or post-surgical,” he explains. Regardless, a veterinarian can help you decide what kind of pain reliever is best for your situation.
“I think what’s going to happen is over time, veterinarians will have most of the pain killers at their clinic, and they’ll help the producer decide.”