Vaccination is intended to prevent disease, although with some diseases, vaccination can only reduce the severity of the illness. The best value in vaccination is in using a program that works with your veterinarian and targets the specific disease risks of your horses. Most disease risks in horses are seasonal. For performance horses, the greatest benefit from vaccination for influenza is likely to occur in the spring. Spring is important because that’s when the risk of infectious disease builds as horses start being exposed to other horses by going to shows, breeding farms, training barns, etc.
That doesn’t mean that fall isn’t important. In Canada, one disease where the risk of infection is greatest in the fall is Eastern Equine Encephalitis (EEE). Cases of EEE usually show up in the late summer and early fall, especially in Ontario and Quebec. Last fall, there were even cases of EEE in Nova Scotia for the first time. Of course horses that travel to the US will be at risk of exposure to EEE earlier in the summer.
Fall is also an important time to revaccinate (or boost) horses that are going to other farms or to fall and winter shows that have had a flu vaccine other than one with proven 1 year duration of immunity. Some flu vaccines do not have proven duration of immunity. They may need to be boosted several times a year in order to achieve protective levels. FEI rules also state that flu vaccines must be given every 6 months, to horses with an FEI passport.
Fall is also the time to start thinking about making sure foals get a start on their vaccination program. By the time they are 4 to 6 months old, foals will have lost much of the immunity they got from their mom (“passive” immunity) and they will need to develop their own (“active”) immunity. The AAEP suggests that foals should be vaccinated beginning, at least, when they are 6 months old. They would need the same vaccines as older horses; tetanus, flu, rhino, rabies, EEE as well as any other vaccines that you and your veterinarian have decided are important. Foals will need to get a booster about a month after they get their first shot.
Pregnant mares are another group that are candidates for fall vaccination. If you vaccinate to prevent Herpes abortion (“Rhino”), then the mare will need to start her 5, 7 and 9 month boosters in the fall. Depending on when the mare is due to foal, she may also need a late fall booster against diseases like flu and rhino to make sure she can transfer peak immunity to her foal in her colostrum.
Whatever the vaccination program, it is important to keep good vaccination records, including the name of the specific vaccine that was used, so that missed vaccinations and misunderstandings about the vaccination program are less likely to occur.
Calvenza ® is the only Flu/Rhino vaccine in Canada that has proven 12 month duration of immunity and contains the most recent OIE-recommended strain of influenza. Once you have completed your horses’ initial series of vaccines, Calvenza can be given once a year. By adding Calvenza to your vaccination program, you can decrease the number of flu/rhino vaccines you are giving and provide excellent protection against flu/rhino.
Vetera® is a new line of West Nile and combination vaccines that contain the most up-to-date strain of West Nile virus and offer 1 year duration of immunity.
Calvenza® and Vetera®offer a Vaccine Assurance program that stands behind the vaccines* (some conditions apply).
Provided by Jennifer Verhulst-Loch; written by Dr Robert Tremblay.
Boehringer Ingelheim Equine