Q. What’s your opinion on whether horse owners should administer their own vaccines?

A. It is important for vaccines to be stored properly to maintain their efficacy. Buying vaccines from a reputable source implies that they are kept properly refrigerated and have not lost their potency. Warehouse or wholesale outlet companies, feed stores or veterinary bulk supply outlets won’t necessarily guarantee proper handling of these products, so you can’t always be assured that your horse will receive adequate immune coverage if you vaccinate with a product from one of these sources.

Having your vet vaccinate your horse assures the vaccine is from a reputable source, that it has been handled properly and kept at proper temperatures during distribution and shipping, and that it is not outdated.

Your vet uses safe techniques for administering vaccines that incur the least risk to you and your horse. Even with a vet’s excellent injection technique, transient side effects such as muscle soreness, fever or malaise can occur, as might an occasional post-injection abscess. Adverse reactions are usually related to an immune response, or to the adjuvant (carrier agent) in individual vaccines, with some vaccine products more reactive than others.

These signs usually pass within 72 hours, and if the best vaccine products available are used, less than one horse in 100 even notices he has received a shot. Based on the sheer numbers of horses your vet immunizes each year, he or she has knowledge of which vaccines have the least likelihood of producing adverse reactions. 

Also, keep in mind that if your horse is insured and you administer any medication—including a vaccine—that induces a life-threatening or fatal anaphylactic reaction due to an incorrect injection technique, the insurance company may not honor your insurance claim.

Expert: Nancy S. Loving, DVM, is a performance horse veterinarian based in Boulder, Colo. She is also the author of All Horse Systems Go.