The first step of planning a vaccination program is deciding what you are vaccinating for and choosing the correct vaccine. Whether you purchase vaccine from a veterinarian clinic or another outlet, you should always check the label for an expiry date and a DIN (Drug Identification Number) that indicates it has been government approved for quality assurance.
There are two different types of vaccines: modified live and killed vaccines. Modified live vaccines contain the live virus and are usually in a dehydrated from that needs to be re-hydrated with a liquid of some kind. They are generally less stable than killed viruses (which do not contain any live virus), require protection from heat or freezing and have a limited lifespan once prepared, so have to be used up right away.
Veterinarians recommend producers use each needle only once. “From a bio-security point of view you should use a needle once and then throw it away,” says Wayne Tomlinson, Extension Veterinarian with Manitoba Agriculture, Food & Rural Initiatives. “In the southeast corner of Manitoba right now there is a disease called anaplasmosis [a micro-organism that is a parasite of red blood cells] that can be spread by dirty needles, so we do have diseases in cattle that can be spread by injecting multiple animals with the same needle.”
As an alternative, however, you could purchase higher-quality, stainless steel needles that can be reused for a number of animals, or multiuse vaccination guns that deliver the appropriate amount of vaccine with each pull of the trigger.
The size and length of needle required will be depend on the product being administered, the age of the animal being vaccinated and the type of injection. Aim to use as small a gauge needle as possible, (the larger the number, the smaller the needle size), for the viscosity of the product. Check how it flows into the syringe when drawing the vaccine up. If you have difficulty or it flows very slowly into the syringe you may need a larger needle.
The needle length will depend on the thickness of the animal’s hide. Generally, says Tomlinson, a inch needle is sufficient for a baby calf, while one to 1.5 inch may be needed for full grown animals.
Whatever needle type you use it is important to sterilise it between animals with alcohol to minimise the risk of infection and transmission of bacteria from one animal to the next. And remember a dull needle is going to hurt, so it also becomes an issue of animal welfare.
ADMINISTERING THE VA CCINE.
There are two ways to administer vaccines: subcutaneously (under the skin) or intramuscular (into the muscle). The instructions on the product should explain which method to use.
Generally a shorter needle (about “) should be sufficient for most subcutaneous injections, whereas intramuscular will usually require a longer needle (one to 1.5”), especially in older cattle, to penetrate the layer of fat under the skin and reach the muscle tissue.
Keep the vaccine in a container (like a cooler with ice or warm packs) to hold it at the recommended temperature.
For the safety and comfort of both the animal and yourself make sure that the animal is correctly restrained in a squeeze or head gate, many of which now come with a neck extender that literally stretches the neck out and holds the animal firmly in place so that the injection can be administered quickly and with minimum discomfort.
All injections should ideally be in the middle of the neck area, in a triangular section in front of the shoulders and behind the ears (see diagram). It is important not to go too far down on the neck as this is where vital organs like the windpipe and arteries are located. Intramuscular injections in particular should not be given in the rump or leg. “In cattle we like to give injections in the neck muscles because that tends to be a poor quality meat and so if we happen to have a reaction of some sort we are not going to damage an area like the hind-quarters, where the better cuts come from,” says Tomlinson. “We need to protect the quality of the food that we are producing. A needle mark, even though you used a new, clean needle, could still leave some scarring in a good cut of meat.”
WHAT CAN GO WRONG
Sometimes needles can break and remain in the hide or skin, but Tomlinson says this can be largely avoided if producers use only new needles for each animal. “New needles seldom break,” he says. “Most of the time when they break it’s because a re-used needle has been bent and straightened.”
Broken needles can be removed by a veterinarian, but it’s not always a viable option for producers to pay the cost of the procedure. If a needle does break during injection, Tomlinson says producers need to identify the animal and make sure when it is shipped for slaughter the processing facility knows the animal contains a needle and its location, so they can look out for it in the meat.
Allergic reactions to vaccinations, although very rare, can happen says Tomlinson, who adds that the most common (as in humans) is anaphylaxis, which causes the windpipe to constrict and inhibits breathing. As the reaction can happen quickly, it’s best to keep a dose or two of epinephrine, which counteracts the reaction, as there will be very limited time available to administer it.
Angela Lovell is a freelance writer based in Manitou, Manitoba.