The use of remote drug delivery (RDD), or "darting," to treat sick cattle in the field, has grown in both popularity and controversy over the past year or two. We recently ran an article on this site titled "Dart failures: Have they happened to you?" The article outlined a research trial at Iowa State University in which four of 15 darts fired at restrained cattle from a uniform distance failed to inject their dose of antibiotic. Following the article, we asked for feedback from readers on whether they had experienced failures with these RDD devices or had comments on RDD in general.
Within just a few days after posting the article, we have received several interesting and insightful comments.
A reader from Oklahoma writes: "I have a cow/calf operation in big rough pastures and darts are very helpful. It is difficult and time consuming to rope or try to drive every animal a mile or more to pen.
Most of my darts fall out in a few minutes and very rarely do I find one that did not inject. I believe if given in the neck they are safe for the cattle and consumer."
Another reader from Kansas relates these experiences: "Thank you, thank you, thank you for doing this article. I have a (RDD) air rifle. It is two years old. Pinkeye was terrible in my area. I have had four darts, that I am aware of, that failed to deliver the intended drug. I emailed (the manufacturer) and received a disappointing reply from them saying if I would return the defective darts, they would replace them, one for one, with me paying the postage. They would then try to replicate my field conditions with the returned darts to see why there was a failure. Are they serious? They are going to replicate my conditions? Wind speed, air temperature, the animal's position in the pasture when the dart made contact, the location of injection, the hide thickness, etc. What a joke. But moreover, I have an animal in need of care and this company apparently doesn't have adequate quality control to guarantee successful delivery of a drug. (The antibiotic used) is nearly $5 per cc. You put it into their 10cc dart, which costs $5 each, and you'd better be damn serious about what you're doing. That's a $55 injection you're sending towards an animal. Also, it's necessary to check the end of the needle as I'm finding a small burr on the point. The biggest problem is, without following that animal around to retrieve the dart, you have no way of knowing how successful your actions were. "You" believe you medicated an animal in need. I just happened to pick up my first failed dart and shook it. The (medication) came out. Horrors. I pulled all the medication out of it.
Don't get me wrong about my rifle. It's been a necessary evil this summer. If not for it, my cattle would have been gathered weekly for the past two months. Imagine the expense of hiring help to do that. 70 pairs in 640 acres would have required several guys on horseback at $200 per day for each. Not to mention the sorting and time through the chute. I did notice the calves have a minimal response to a dart but the mature cows' reaction is very dramatic. I have not had any issues with infection or abscess' with dart drug delivery.
I will also make it clear, I have kept my rifle very clean and have followed all instructions that came with the rifle and what can be found on (the manufacturer's) website. Thanks and I am looking forward to what you learn from others on this subject."
Another reader offered these thoughts. "On the topic of RDD using darts, I have doctored hundreds using this method and have never had trouble getting the drug in the cattle, or at least not had trouble getting the cattle over sickness using the dart. As for lesions or abscesses popping up afterwards, I have seen minimal issue. Much of this is dependent on the art of delivery including distance, angle of the shot and length of the needle.
This study was flawed #1 because they used the wrong length of needle. He should've been using a 1/2inch not 3/4. #2 I would say that, depending on the type of gun, they were most likely too close and shot straight on as opposed to trying to deliver at an angle, similar to the way one would with a syringe.
The question that needs asked is what percentage of vaccines are not delivered properly in a chute? My guess is it might be higher than 4 out of 15.
RDD through using darts is one of the best tools ever created for keeping cattle healthy when used correctly. The amount of stress it removes from the cattle by not wrestling them up in a chute or roping them far outweighs the negatives."
A reader from East Texas shares these experiences from using darts on a cow-calf operation."I routinely use 5 and 6 ml 3/4" needle darts on 200- to 500-weight calves. The tool has dramatically reduced calf loses, reduced herd handling stress and made my work much safer. I have never had a dart fail to administer meds. I have shot hundreds of them. Darts normally fall out in 10 to15 minutes, I pick up every one and check to see if dart fired.
The study presented is giving very different Intel than I have experienced with long term use in the field. I suggest to repeat the study."
A rancher from Montana shares these thoughts. "I was interested in your dart article. I have used the darts for five years. The first year I had the dart gun I treated over 70 calves for pneumonia after we preconditioned. Didn't lose a calf. I have had darts stay in for 24 hours. There was more swelling around this site. I have found the darts will not work well on calves younger than 2 months of age. The darts bounce off animal. I think the skin is too thin. Most of my shots are placed from around 20 yards.
If I dose the animal properly it is an effective tool. I very seldom have to retreat the animals."
Finally, a stocker operator writes: "I have been using darts for doctoring sick stocker calves (300 to 400 pounds) for about 10 years and have suspected a high failure rate of detonation . Your failure rate of approximately 20 percent does not surprise me! What can be done to make the darts more reliable?"
We are still interested to hear from more readers on this topic. What have you seen in the field, with either your own or your clients' use of RDD? Please send your comments to me at email@example.com.
Watch for the September issue of Bovine Veterinarian for more comprehensive coverage of RDD cautions and suggestions for minimizing risk in RDD use.