by John Maday
Steady rains have turned a distant pasture into a swamp. Foot rot begins to break out in the cattle, but the conditions make transporting sick cattle to a treatment facility unrealistic. Access is possible on horseback or with an ATV, so the crew grabs a dart gun or “projector,” loads some darts and treats affected animals with antibiotics from a distance, without capturing or containing them.
Increasingly, ranchers use pneumatic darts or remote drug delivery (RDD) systems for medicating cattle—sometimes as a last resort, sometimes for simple convenience. Meanwhile, Beef Quality Assurance (BQA) experts worry the industry could be squandering decades of progress in minimizing injection site injuries, potential drug residues and other BQA achievements by rapidly adopting RDD.
So, did the crew with the distant foot rot cattle do the right thing by turning to RDD? That depends. Did they use the medication according to label instructions and was the correct dosage of the drug delivered to the animal? Was the drug delivered to the label-specified tissue: intra-muscular (IM), subcutaneous (SQ) or intravenous (IV)? Was the injection site in compliance with BQA guidelines? Can the producer ensure no foreign objects, such as broken needles, remained in the animal following RDD?
Based upon these and other questions, NCBA and the Beef Checkoff issued a BQA advisory this past year, on darts and RDD, expressing a long list of concerns over the use of the devices, particularly for the delivery of antibiotics.
The darts typically are fired from a pistol or rifle, some powered by air, using a hand-pump mechanism to regulate power. Others use a .22 caliber blank cartridge to propel the dart. Upon impact, a charge at the rear of the dart fires to inject the medication into the animal.
Kansas State University veterinarian Mike Apley says the industry has moved too quickly and went too far in adopting the technology before fully studying its impacts.
While he believes the risks are significant, Apley acknowledges that use of RDD devices will continue. With that in mind, it becomes the responsibility of individual users to work with veterinarians to determine what constitutes “appropriate use.”
Veterinarian Dee Griffin, now at Texas A&M after a long career at Nebraska’s Great Plains Veterinary Education Center, has compiled a detailed list of concerns with RDD, along with recommendations for the rare cases in which dart use might be justified. He notes RDD use has grown exponentially in recent years, with dart sales numbering in the millions. Yet, “darts for delivery of medication or vaccines to animals intended for food are not under any circumstances or in any way recommended, approved or condoned by any veterinary organization,” he says.
Griffin stresses the importance of following BQA guidelines for medication use. In situations where remote delivery of medication must be used, it should comply with the National BQA Guidelines and label requirements for injection-site selection, routes of administration, needle selection, medication selection, medication volumes, keeping proper medication use records and actions required should a needle break and leave metal in the animal. Darts inherently complicate all of those compliance points.
Among Griffin’s warnings about RDD use, these points stand out:
- Dart use to deliver fluoroquinolones, ceftiofur, or compounded medication (mixed or diluted other than specifically instructed on the label) is illegal and considered a criminal act according to the Food and Drug Administration.
- Tests have shown a single dart can deliver antibodies below the skin and in the muscle. Most antibiotic labels specify either SQ or IM use, not either or both, so delivery of those products with a dart could constitute illegal, extra-label use. One exception is oxytetracycline, but there are no darts sufficient in size to accommodate the dosage requirement of that drug.
- Any extra-label drug use requires the direct oversight of a veterinarian within a valid veterinarian-client-patient relationship (VCPR). These regulations require the use, including route of administration of all prescription medications to strictly follow the written directions of the veterinarian prescribing the drugs.
- There are confirmed reports of darts and dart components found in beef carcasses at packing plants. Adulteration of food with metal violates food safety regulations and is prosecutable.
- There are confirmed reports of injection site abscesses resulting from medication dart usage. These are likely caused by using unsterile darts or contamination while filling the dart with medication.
- There are confirmed reports of violative drug residues traced to medication dart usage.
- The BQA-approved location for IM and SQ injections is in the neck, which presents a relatively small target. Even a near miss could seriously injure the animal. Targeting other areas, such as the hindquarters for dart injections, is not acceptable from a BQA standpoint.
Researchers at several universities are evaluating RDD systems for drug delivery, efficacy, impacts on meat quality and more.
Results of some studies are pending, but Iowa State University researchers recently completed a trial in which they used RDD to inject restrained cattle with a 10 mL dose of antibiotic fired from a uniform distance. In that test, four of 15 darts failed to inject the antibiotic.
Source: Drovers September 2016