Immunity is the ability of an organism to be able to resist and destroy micro-organisms. Just as humans do, horses have 2 forms of immunity: natural and acquired immunity. As you might suspect, natural immunity is the horse\’s inborn ability to resist disease and infection. Acquired immunity comes from natural exposure to disease carriers, recovery from an infectious disease, antibodies obtained via the placenta or ingested through colostrum at birth, or vaccinations given to the horse to product antibodies against a specific disease.
Despite the fact that the snow may already be flying where you live, if you haven\’t yet vaccinated your foals this year, there\’s still time. The important thing is to get it done! When incorporated into a program that includes regular deworming, a good nutrition program and a safe environment, your foals will be aimed towards to a healthy future.
So when it comes time to book your veterinarian appointment, what vaccines should you ask for, for your foals? Well, there are several specific immunizations needed but many depend upon your foal\’s age, exposure risk, value, general management and geographic location. Your best bet is to discuss a protocol with your vet. However, here are a few basic considerations:
1. TETANUS – Tetanus is caused by toxin-producing bacteria present in the intestinal tract of many animals and found in the soil where horses live. Spores enter the horse\’s body through wounds or the umbilical cord of newborn foals. Tetanus is a constant threat to horses and humans and as such, horses should be vaccinated against it annually. Foals can receive their first tetanus vaccine as early as 6 months of age if the mare was vaccinated within 30 days of foaling, or 3 months of age if the mare was not vaccinated. Talk to your vet.
2. ENCEPHALOMYELITIS – This disease is often referred to as \”sleeping sickness\” and caused by Western Equine Encephalomyelitis (WEE) or Eastern Equine Encephalomyelitis (EEE). These two strains of the disease have been seen throughout North America. A third version, Venezuelan Equine Encephalomyelitis (VEE) has recently been seen in Mexico. These diseases are usually transmitted via mosquitoes and the symptoms vary a great deal, however they are result in the degeneration of the brain. Foals can be vaccinated at at 6 months of age if the mare was vaccinated within 30 days of foaling, or 3 months of age if the mare was not vaccinated. Talk to your vet and specifically ask if your foals need a encephalomyelitis booster.
3. INFLUENZA – This is one of the most common respiratory diseases in horses and the virus is highly contagious. Horses that travel or are exposed to high horse traffic should be vaccinated regularly against it. Flu viruses can result in nasal discharge, fever, coughing and loss of appetite. The disease can be expensive to treat and it usually very uncomfortable for your horse to endure. Foals can be vaccinated at 6 months of age if the mare was non-vaccinated. Often, this vaccine is given in combination with the rhinopneumonitis vaccine. Which brings me to my next bullet point…
4. RHINOPNEUMONITIS – It\’s important to know that there are 2 very different disease viruses: equine herpesvirus type 1 (EHV-1) and equine herpesvirus type 4 (EHV-4), that cause 2 different diseases, which are both known as rhinopneumonitis. Both cause respiratory tract problems, however EHV-1 can also cause abortion in pregnant mares, foal death and paralysis. As mentioned above, foals can be vaccinated at 6 months of age if the mare was non-vaccinated. Speak to your vet about Flu / rhino boosters.
5. STRANGLES – No matter where you live, Strangles is a highly contagious disease you should hope your foals never have to deal with. That\’s we vaccinate our entire foal crop, every year within the first year of its life. Now if your foal does contract this disease, consult with your veterinarian for a treatment protocol. If your foal has contracted Strangles in the first year of its life, ask your veterinarian about vaccinating this animal specifically – some vets think the horse may receive enough immunity from being exposed to the disease in the first place.
There are some side-effects associated with the vaccine, which is a modified live virus – meaning the virus cannot cause serious disease in the horse – allowing it to provide longer lasting protection. However, as such this class of vaccine is often not recommended for pregnant mares. The efficiency of this vaccine has been questioned by many vets because outbreaks can occur even in vaccinated herds. However, we have always remained under this steadfast rule with our own horses: \”Even if our horses do contract the disease after immunization, the outbreaks of the disease will be less severe than if we didn\’t vaccinate then.\”
This vaccine is given intra-nasally and can be given to foals starting at 6-9 months. This vaccine requires a booster administered 3-4 weeks after the initial intra-nasal shot has been given.
6. RABIES – Rabies is a scary disease that always results in death. Luckily, it is more prevalent in some areas than others – concern areas include southern Saskatchewan and Arizona, therefore our entire herd receives an shot against Rabies every year. If you also choose to vaccinate your foals against rabies, your veterinarian may not want to administer it on the same day as other vaccines as some serious health threats can occur. Foals can vaccinated against rabies at 6, 7 and 12 months of age if the mare was vaccinated.
In summary, it is my personal belief that there\’s really a lot to gain, and everything to lose when it comes to vaccinating your foals.