It’s that time of year again, time to think about your equine partners and get their vaccines up to date. Whether you chose to have your veterinarian administer the vaccines or do them yourself is up to you, but you should think
about your individual requirements. We have lots of people coming to our clinic and they ask for vaccines for their horse but they don’t really know what they want or why they are vaccinating.
So here are a few questions that should help making the decision easier.
1. What age is your horse?
2. What is your horses current vaccine status?
3. What do you do with your horse and where does it live?
4. Are you showing?
5. Are you traveling?
6. Do you have a budget that limits what you can vaccinate for?
Before we answer these questions, let’s think about what we are vaccinating for:
To me preventable diseases fall into two categories:
those that are transmitted by the environment and those that are transmitted from other horses.
If your horse never leaves your property and there are no other horses around you, you likely don’t have to worry about the second category.
Unfortunately there is little you can do about the first category as your horse lives outside on dirt and unless you keep him in a mosquito-proof enclosure, there will be contact with parasites.
A. Diseases Transmitted by the Environment you Horse Lives in:
1. Tetanus – tetanus is a fatal disease to horses, so in my mind there is no reason not to vaccinate for it. The disease is transmitted by deep wounds or punctures that lets a bacterial organism called Clostridium tetani into the horses tissues. This organism then secretes a neurotoxin that results in muscle rigidity and eventually death from respiratory failure. The vaccine is very effective and inexpensive, we see very few side effects from this vaccine. After an initial booster, the vaccine is an annual intramuscular injection.
2. EEE and WEE (Eastern and Western Equine Encephalitis) – A viral encephalitis transmitted by mosquitoes. Horses with this disease first spike a fever, then become lethargic and blind, staggering and eventually progress to seizures and death. The primary reservoir host for the virus are birds. Again, the vaccine for this disease is very protective and inexpensive. Unfortunately duration of immunity is short (4-6 months). Any horses traveling to areas where mosquitoes are present year-round will need vaccines at least twice a year. This disease is zoonotic, meaning it is transmissible to humans
3. West Nile Virus (WNV) – A viral disease transmitted by mosquitoes. The reservoir host for this disease are birds. And yes, we do have this disease in the East Kootenays! Annual re-vaccination is highly protective.
4. Potomac Horse Fever (PHF) – This is a parasitic disease that is transmitted either by a freshwater snail or a sand fly. We have seen this disease in the East Kootenays, generally in the late fall with horses in close vicinity to the Kootenay River. Horses develop profuse diarrhea and will succumb to this parasite if they are not treated appropriately. The vaccine is given annually.
B. Diseases Transmitted by Other Horses
1. Equine Influenza Virus – As in people, this viral condition results in fever, depression and respiratory symptoms. It is transmitted through aerosol transmission and contact with contaminated surfaces. Vaccination every 6 months gives some protection, both intramuscular and intranasal vaccines are available.
2. Equine Herpes Virus (Rhinopneumonitis) – This virus (at least 9 different types of EHV have been identified) can cause several types of clinical disease. Respiratory disease with a high fever, coughing and nasal discharge is the most common form we see and the strain we vaccinate for with the intramuscular vaccine every 6 months. The virus can also cause neurological disease but there is currently no vaccine available to protect from this form of the disease. Yet another form affects pregnant mares with abortions in the last third of their pregnancy. There is a vaccine available for broodmares and it should be given at 5, 7, and 9 months of pregnancy. The primary mode of transmission for this virus is from horses that are shedding the virus but are not actually clinically sick. Once a horse has recovered from this disease they will intermittently shed the virus at times of stress.
3. Strangles – A bacterial disease affecting primarily the lymph nodes of the head and neck. The organism is contracted from nasal secretions of sick but outwardly healthy horses. The bacterium (Streptococcus equi ssp.equi) will persist in the environment for extended periods of time. When lymph nodes other than those on the head are affected, the term “bastard strangles” applies. Some of these animals develop internal abscesses that cannot be drained and succumb to this disease. An intranasal vaccine given annually provides good protection.
To make things even more complicated, there are numerous combinations of vaccines for these diseases available. And if your horse has never been vaccinated for these diseases, all these vaccines need to be boostered.
Here is a list of the vaccines we carry at Tanglefoot:
A. Tetanus Toxoid
B. 3-way vaccine – includes tetanus and EEE and WEE
C. 4-way vaccine – includes tetanus, EEE, WEE and West Nile Virus
D. West Nile vaccine
E. Fluvac – intramuscular vaccine against influenza and herpes virus
F. Flu-Avert IN – intranasal vaccine against influenza virus
G. Calvenza – intramuscular or intranasal vaccine against influenza and herpes virus
H. Pinnacle IN – intranasal vaccine against Strangles
I. Potomoguard – intramuscular vaccine against Potomac Horse Fever
J. Prodigy – intramuscular herpes vaccine for broodmares
As you can see, there are many factors that need to be considered when developing a vaccine protocol for an individual horse. So here are our recommendations for your equine friend:
Pleasure/Backyard Horse – bare minimum vaccine for these guys should be a 4-way vaccine. If your pleasure horse goes out and meets other horses you should consider adding something for flu/rhino. If you are boarding indoors for the winter, boost your flu/rhino and give a Strangles vaccine in the fall. If you live near the river, vaccinate for PHF.
Show/Travelling Horses – The biggest thing about the showing horse is to vaccinate for anything you could come in contact with while on the road. And do it a few weeks before you head to your show so if your horse gets a sore neck from the vaccine you are not having to scratch. Put your horse on a 6-month schedule – in the spring they get a 4-way vaccine, a flu/rhino vaccine, then in the fall you boost the flu/rhino and give them a Strangles vaccine as well. Again if you live near the river you should add PHF to your protocol, I usually recommend giving the vaccine in the summer months to get optimal protection in the fall.
Foals – if you have done things right, you foal should be protected from the antibodies it received from the mare’s colostrum until about 4 months of age. Start vaccinating at that point; they should receive a 4-way vaccine at 4 and 5 months of age. You can also start vaccinating for flu/rhino as well as Strangles and PHF. Often we will stage vaccines as little foals tend not to love being pin cushions. We may move some of these things up in the face of an injury or an outbreak in your area.
Broodmares – ideally your broodmare should be fully vaccinated (as above for show horses) prior to being bred. To protect her from abortion due to herpes virus, you should give your broodmare a Prodigy vaccine at 5, 7, and 9 months of gestation. About a month before she is due, you need to give her a 4-way and intramuscular flu/rhino vaccine to make sure the foal gets high levels of antibodies in her colostrum.
We hope this makes it clear why you should be well informed before you come in and request vaccines for your horse! There is so much more to consider. One part I have not touched on yet is the cost of some of these vaccines. It can add up pretty fast, but the general rule is that prevention is significantly cheaper than treatment. And not all horses recover with treatment, can you afford to lose your athlete and best friend?
Occasionally horses will react to one vaccine but might have no problem with another product. Depending on the degree of the reaction, we have to make a decision whether the risk of the disease outweighs the risk of a reaction.
We are happy to discuss an individual program that best fits you, your horse and your budget!
Make an appointment with one of our veterinarians to chat about your situation if you are not sure what you need.