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Resflor – for Sep. 6, 2010

Many of us recall a time when several combination drugs were on the market for cattle. There were drugs such as Pen-Strep or Azimycin, which was a combination of two antibiotics, a steroid and an antihistamine all in one bottle. All these products have since been pulled in the interests of meat safety and beef quality.

Today though, with more concerns about animal welfare, we often prescribe an anti-inflammatory slash painkiller together with the antimicrobial we are about to use. Veterinarians try to replace steroids with an NSAID (non steroidal antiinflammatory drug). There are generics out now as well as other families of NSAIDS. Flunixin or Banamine was the first one on the market. But Resflor is the only new combination drug to be approved in some time. It is a combination of Banamine and another previously approved antibiotic florfenicol, which is marketed under the trade name Nuflor. As with all such drugs you require a prescription and a valid VCPR (veterinary client patient relationship) in order to purchase it.

The benefit of any combination product is fewer needles need to given. In keeping with the principles of beef quality assurance, the company (Intervet Schering Plough Animal Health) has licensed Resflor for subcutaneous use only, at the same dosage as Nuflor (6 cc per 100 pounds). The blood levels persist for four days.

There are several interesting things to note about this product. While the spectrum of organisms it is effective against is the same as Nuflor, the blood levels are reached quicker and stay higher for the first 24 hours than with Nuflor alone. This is most likely the result of the anti-inflammatory effect of the flunixine, which allows the drug to more quickly penetrate the site of infection.

Resflor is primarily approved for respiratory pathogens. Clinically cattle will look better as the flunixin decreases the pyrexia (fever), improves the clinical depression and greatly improves the animal’s ability to breathe. This then allows time for the antibiotic to start working. As a result the combination product decreases the amount of lung tissue that becomes consolidated (solidified). Once a portion of the lung becomes consolidated it loses its ability to take in air. Hence cattle with more consolidation do poorly as far as growth is concerned. This consolidated tissue

may also abscess resulting in a reoccurrence of pneumonia down the road. The sooner pneumonias are treated and the less resulting consolidation or scarring and adhesions of the lungs the better.

Because this is the first combination product on the market for several years Health Canada’s Veterinary Drug Directorate has made the slaughter withdrawal time slightly longer than for Nuflor alone. The withdrawal has been set at 60 days. With that it is not to be given to any dairy cattle, milking or dry, and no veal calves as well. As mentioned earlier this product is also a prescription product so it must be used under a direct veterinary-client patient relationship. It will primarily be used for respiratory disease on calves or light feeder cattle where the 60-day slaughter withdrawal is easily followed. In most cases heavy feeder cattle will need other products with shorter or no withdrawal periods.

In doing some of the approval work it was found that penetration of the antibiotic into areas such as skin, muscle, soft tissue in the foot as well as the brain and areas around the eye will make it useful in treating a large number of maladies. It will be up to you and your veterinarian to discuss these conditions. With time more of them may appear on the label.

It should be noted as well that unlike Banamine by itself, which is given intravenously, this combination is given subcutaneously and produces little swelling at the injection site. At 6 cc /100 lb. it is quite a large-volume injection. In larger calves I would split that over at least two injection sites. The actual recommendation is no more than 10 cc per site. It is still relatively thick like Nuflor so it must be kept warmer in winter and given with a larger bore needle, 16 gauge, to overcome the poorer syringability.

The Banamine dosage in Resflor is formulated to be the same as the 24-hour dosage of 2 cc per 100 lb. if given individually. What this means is the Banamine will last better than 24 hours, which is often all you need.

Price-wise it is cheaper than applying the two products separately so over time I suspect Resflor sales will pretty much take over from Nuflor. It has all the benefits you and your veterinarian have derived from Nuflor with the added benefits of a NSAID.

For all these reasons it is a welcome addition to today’s arsenal of products developed primarily for bovine respiratory disease.


While the spectrum of organisms it is effective against is the same as Nuflor, the blood levels are reached quicker and stay higher for the first 24 hours than with Nuflor alone

About the author


Roy Lewis is an Alberta-based veterinarian specializing in large-animal practice. He is also a part-time technical services vet for Merck Animal Health.



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