Observing proper technique can limit the occurrence of sterile abscesses at vaccination sites.
First, Last, And Always... Read And Follow Label Directions!
Use only fresh product - Every vial of C/D&T vaccine that I have seen states that leftover product must be discarded instead of saved for future use. The fact that the sealing power of the stopper has been compromised by sticking needles through it is only one of the reasons.
Avoid off-label or extra-label use. Be very cautious about using vaccines in an off-label or extra-label manner. These products have not been proven to be safe or effective and tissue damage is more common with uses of this type.
Do not combine vaccines to make your own combinations unless the labels say to do so.
Watch expiration dates. Always check the vaccine's expiration date a few days *before* you intend to use the product. Otherwise you'll end up like me every season... bringing in the goats to immunize only to find that your only vials of vaccine expired six months ago.
Store vaccine properly. Read the label and follow all instruction regarding storage, mixing and handling of vaccines. Heat, sunlight and freezing destroys almost all vaccines. When working outside carry and keep vaccines in an insulated ice chest with frozen ice packs. The ice chest will also keep dust off the vaccine vials.
Reject abused products. Vaccines that arrive to you on a hot day in the summer without frozen ice
packs should be sent back.
Use the right tools. For C/D&T use 20 to 22 gauge needles, 1/2" to 1" long.
Thoroughly mix the product. Most vaccines come in two or more parts. Some vaccines, like C/D&T, are stored and shipped with both parts in one vial. The active ingredient is usually a solid which separates from it's liquid carrier during storage. The two parts must be mixed together - shaking the vial usually does the job. Don't withdraw the dose immediately, though: Let the vial rest long enough for air bubbles to rise to the top so you don't draw them into the syringe.
Clean the vial stopper with alcohol before each insertion of a needle. Dust and other contaminants adhere quickly to the top of an unprotected vial.
Clean the skin before administering the injection. Think about the dirt and nanny berries that the goat was laying or rolling in fifteen minutes ago. The dirt probably won't harm the goat as long as it stays on the outside of the skin but, stick a needle through that skin and you'll assuredly introduce some of the dirt into the goat.
Inject properly The vaccine should end up between the skin and the muscle. Pull up a "tent" of loose skin between your thumb and index finger and insert the needle into the tent. Insure that the needle is all the way under the skin and that it does not stick out on the other side. Injecting between layers of skin will almost always result in an abscess.
Rub the injection site to distribute the vaccine to a wider area under the skin. If, after rubbing, you still have the same size lump as you started with it probably means that you injected the vaccine between layers of skin instead of between the skin and the muscle.
Don't reuse disposable equipment. Disposable needles and syringes are not designed to be reused.
One goat, one needle - The avenues for contamination are very *wide* when you use a needle more than once without cleaning it. Sticking a needle into a goat, withdrawing it and subsequently sticking the same dirty needle into another goat just doesn't make any sense. If you are not using automatic dosing equipment you would also have to stick that dirty needle into the vial to draw up the second goat's dose.
Don't invite contamination. Never leave a needle and/or syringe in the top of any medication or vaccine bottle. This can lead to contamination of the bottle contents, the needle, and the syringe.
The above methods seem to have worked well for us over the years. Hope they work for you.