Needle & Syringe Selection, Vaccine Care, All Important in Injection Management

by Jill J. Dunkel

Since the 1991 National Beef Quality Audit highlighted injection site blemishes as a major concern, the feedyard industry has worked diligently to move injections to less valuable locations on cattle. Due to their efforts, the problem in feeder cattle has been largely eliminated, with lesions in only three percent of calves, according to Dr. Todd A. Thrift, Assistant Professor and Extension Livestock Specialist with the Texas Agricultural Extension Service. "It is a true BQA (beef quality assurance) success story," Thrift says.

But other quality defects caused by improper injection management are a concern. Needle and syringe selection, management of the vaccine, and product interaction are also important. Some problems are a safety issue, like broken needles, which can result in a danger to the consumer, not to mention possibly turning off that consumer from beef forever.

Often broken needles are the result of an animal jumping in the chute as the injection is being administered, therefore, proper restraint of that animal is key. "Needle selection can also play a very large role."

Needle Selection

"A smaller needle is much more likely to break," says Thrift. "Because of that, I don't recommend using 20 gauge needles. 18 gauge are also prone to bend if the animal jumps in the chute." As a general rule, Thrift recommends a 16 gauge needle for most sub-Q and intramuscular (IM) injections. "They are harder to bend."

Thrift also cautions against straightening bent needles. "Straightening a needle weakens it even more, increasing the odds it will break. If a needle bends, throw it away," he says.

Broken needles should be removed from the animal immediately, Thrift says. "Broken needles migrate in tissue, like a mini-knife. It is impossible to know where it could end up."

When deciding the length of the needle, it is important to consider the size of the animal you are vaccinating, Thrift says. "For IM injections, I use 11/2 inch needle for fat cows or bulls, but a 1 inch needle is good for the majority of cows and calves. A longer needle could go all the way through the neck of a light weight calf."

For Sub-Q injections, Thrift's needle of choice is a 5/8 inch B bevel needle. "A B bevel is designed for sub-q administration because it has a shorter edge, making it easier to get the injection under the skin. The bevel is less likely to pick up the top layer of muscle tissue." However, even with the use of a B bevel needle, Thrift recommends tenting the skin to ensure a good sub-Q injection.

Syringe Selection

Syringes are another important aspect of injection management to consider. "Disposable syringes work fine, however a lot of time can be spent refilling if several head are to be vaccinated. Plus, if the same needle is used to administer the injection as well as draw the vaccine, you are risking contaminating the vaccine. This is especially important because blood-borne diseases could be spread from animal to animal.

"This can be prevented by using one needle to draw the vaccine and another needle to inject with, however, this takes a long time and few people are willing to take the extra steps," Thrift says. He recommends buying small dose vials so that fewer doses will be contaminated if a disposable syringe is used.

Multi-dose syringes eliminate the contamination problem if the needle is changed with each draw of vaccine. Considering needles should be changed every 10 to 12 head --15 head maximum -- changing needles when refilling the vaccine is good needle management, anyway, says Thrift.

Multi-dose syringes are designed to administer a 5 ml dose, however they can be adjusted for a 2 ml dose, but Thrift recommends monitoring the injection. "With the 2 ml dose, the trigger does not pull back all the way as with a 5 ml dose. Sometimes it doesn't feel like you're giving much."

However, Thrift says multi-dose syringes allow for good vaccine practices, such as keeping the vaccine cool and in the dark. It is important to keep the bottles cool chute-side to preserve the vaccine. "After an hour of being rehydrated, modified-live products decline."

Continuous feed syringes eliminate vaccine contamination problems because the bottle is only tapped one time, and the syringe is always ready for the next injection, saving time. They are especially useful in mass treating a pen of cattle. If using a continuous feed system with a vaccine, Thrift cautions that the vaccine can get warm, depending on the type of continuous feed system used. "Vac-Pac has a system that keeps the vaccine bottle insulated, which is a definite benefit to a continuous feed system," Thrift says. Regardless of the system, he recommends shaking the bottle periodically to keep it well mixed.

Vaccine Management

To preserve the efficacy of a vaccine, Thrift recommends using small-dose vials. "Smaller dose vials are more likely to get used before the bugs begin to die off with a modified live vaccine. Plus, left over modified live can not be saved -- not even until that afternoon -- so with little bottles, you throw away a smaller portion of the unused vaccine." Thrift recommends buying small doses of blackleg vaccine as well. "You can save blackleg for about a week after it's tapped, but not any longer."

To prevent vaccines from interacting once they are in the animal, Thrift recommends isolating any modified-life products. "I try not to place a modified live next to another injection, either sub-Q or IM." Depending on the processing regimen or treatment required, he recommends placing each injection at least four finger-widths apart, if possible, depending on the size of the animal.

"Injection site management is just another part of beef quality assurance," says Thrift. By considering needle and syringe selection and observing proper vaccine management, products retain their efficacy while injection blemishes continue to decline. Then both the producer and consumer win.