Lisa Guenther, Editor, Canadian Cattlemen, The Beef Magazine
(Previously published in the Canadian Cattlemen, The Beef Magazine: November 7, 2019)
Getting the most out of a vaccine starts with the syringes and needles.
Dr. Cody Creelman, a bovine veterinarian in southern Alberta, recently held a free webinar on ways to make cattle vaccines more effective. Part of his webinar covered how to keep needles and syringes clean and working well.
Creelman recommends checking and replacing o-rings in multi-dose syringes regularly.
“I can’t count the number of times that I’ve started a preg test, and the producer hasn’t looked at their multi-dose vaccine syringe in a year. And he goes to fill that vaccine up with the first 25 doses, and it just all pours down his arm and his hand.”
Before vaccinating, calibrate syringes with water to ensure they’re delivering the right dose. Set the syringe for two ml doses and deliver a few doses into a disposable syringe, measuring the output.
A modified live virus is a living organism, making it vulnerable to not only temperature extremes, but also contaminants. For that reason, any multi-dose syringes that have been used for antibiotics should not be used for vaccine.
“If you put vaccine into that syringe now, you will completely deactivate all of the vaccine, even if you rinse it. It is nearly impossible for you to clean tetracycline residue off the inside of that barrel,” says Creelman.
“Once it is an antibiotic multi-dose syringe, it stays an antibiotic multi-dose syringe. Make sure that you mark those things.”
Producers should also make sure they have the right needle length and gauge, as the correct specs will vary with animal size and injection type.
Have equipment on hand to protect vaccine from temperature extremes on vaccination day. There are commercial products available, but a Styrofoam cooler, with heat packs in the winter and cold packs in the summer, will do the trick. Creelman also advises against storing vaccines in the fridge door, due to the temperature swings when the door opens.
Discard any bent or burred needles to prevent them from breaking inside the animal. Producers should also change needles throughout the day. How often depends on the disease risk in the herd — dairy producers dealing with certain diseases would want to change the needle with every animal, for example.
Most beef herds can get away with changing the needle every 10 or 15 head, Creelman says. His rule of thumb is to at least change it before refilling the syringe, which is a bit of a longer interval than 15 head, but is generally still acceptable in Creelman’s opinion.
Creelman says it’s important to keep everything as clean as possible. That means replacing a needle that has been used to vaccinate animals before refilling the syringe, or using a transfer needle. Using a dirty needle to refill the syringe with vaccine presents several risks.
“You contaminate that bottle. You contaminate other animals. You can cause abscesses. You can do disease transfer.”
Keep the vaccine bottle clean as well. If manure finds its way onto the top of the vaccine bottle, it’s not good enough to wipe it off with a rag. Creelman points out that when vaccinating people, the health nurse cleans the top of the vaccine bottle with an antiseptic wipe.
“That is not overkill,” he says.
After vaccinating, it’s important to clean and sterilize syringes and needles properly. Producers can use detergent on the outside of the syringe, as Creelman says it should be “spic and span.”
But don’t use disinfectant or soap inside the barrel of the multi-dose syringe. Doing so deactivates the vaccine.
“You cannot rinse those things enough to clear off any sort of contamination. It’s just absolutely impossible. You do not want any soap going inside that barrel.”
Even minerals from tap water can deactivate a modified live virus vaccine, so ideally producers should use distilled water to rinse out the barrel.
“That’s how sensitive vaccine is.”
Needles can be sterilized in the microwave. An article previously published in the Western Producer recommends at least 250 ml of distilled water to cover the needle. Microwave on the highest setting until the water boils. Heat the needle for another minute. Make sure the needle stays fully submerged.
Alternately, wrap the needles in layers of wet paper towel. Put everything in a freezer bag, leaving the bag partially open. Microwave for at least two minutes, making sure the paper towels stay moist. Steam should swell the bag before escaping through the opening.
To sterilize a plastic syringe, fill it with distilled water. Wrap with at least six layers of wet paper towels and place in an unsealed freezer bag. Heat for five minutes. Make sure the paper towel remains damp. Squirt out any remaining water.
Syringes and needles should be stored in a clean, dust-free environment after cleaning. Creelman has seen vet clinics in the U.S. that clean, autoclave and store multi-dose syringes for their clients.
However, producers can also put them in a freezer bag and store them in the deep-freeze, as it’s dry, aseptic and won’t hurt the syringe.
“It is a great option.”