Vaccinations

Vaccinations

Why should you vaccinate your horse?
You pay for us to come out, year after year, rain, sleet and shine, to administer a small injection taking a few moments. So is it all worth it? Well………..yes! A good vaccination protocol is essential to your to horse’s health. A horse suffering from tetanus has a less than 10% chance of survival, and the latest outbreak of equine influenza in Australia in 2007 cost over £18 million (not including cost of treatment) and resulted in the death of nearly 40% of affected foals.

Why do we vaccinate and what diseases are we protecting our horses against?
In the United Kingdom we advise vaccinating your horse against two diseases, tetanus and influenza. Both of these diseases can be severely harmful and even potential killers so preventative therapy is far more cost effective and safer for your horse than treating your horse if he gets sick. With regards to influenza, there are also legal requirements with regards to vaccinating your horse if you intend to compete him.

Equine Tetanus Infection

What is tetanus?
Tetanus is a bacterial infection. The tetanus bacterium (Clostridium tetani) can survive for long periods of time in the soil and is highly resistant to heat and light, and can only survive in areas of little or no oxygen, such as nail punctures to the sole.

What are the symptoms?
Symptoms usually take one to three weeks after infection to appear, but in rare cases it may take several months. The infection affects the muscles. A gradual progressive stiffness is the usual presenting sign. Other signs include a startled expression with flaring of the nostrils. As the infection spreads, the horse will suffer from head spasms and therefore have difficulty eating (hence the colloquial term of lockjaw). He/she may also have erect ears and the tail will be held out. Horses with tetanus infection also tend to have heightened reflex actions triggered by sudden noise, become easily frightened and can go into more violent spasms. People who have recovered from tetanus describe the muscle spasms as the worst cramp you can possibly imagine lasting for several days. The horse will also have an increased body temperature up to 43oC (109.4oF) as well as increased heart and breathing rates. Most unprotected horses do not survive a tetanus infection. Those that are lucky enough to recover often have complications and require 6-8 weeks recovery time.

Is it infectious and how is it transmitted?
The tetanus bacterium can survive in soil and environment for long periods of time. Horses are at risk of contracting the disease from any type of wound e.g. from a barbwire cut to a nail in the hoof. Tetanus cannot be passed from one horse to another or from horses to humans.

What can I do to prevent my horse from getting tetanus?
Vaccination is very effective at preventing tetanus. Good stable management is also key, including checking fencing and clearing all potentially harmful material from stables, paddocks and yards. Regular inspection of horses’ hooves and lower limbs will help identify any potential sites of infection requiring treatment.

The vaccine can be administered from 5 months of age. Two doses are administered 4 weeks apart, followed by a third vaccine 12 months later. Booster vaccines are required every 2 years.

Equine influenza infection

What is influenza?
The equine flu virus causes equine influenza. This is a virus that only survives for short periods of time in the environment. It is similar to human ‘flu’ and exists is a number of different strains.

What are the symptoms?
Signs of influenza infection include fever (103-105oC), clear nasal discharge, depression, poor appetite and a dry deep cough. Most horses recover in 2-10 days without complications. In foals it can cause a severe pneumonia that can easily be fatal.

Is it infectious and how is it transmitted?
Equine flu is highly contagious. It is spread in secretions form the nose of affected horses. It most commonly affects 2 and 3 years old horses that have not had time to develop their own immunity to the virus. Luckily equine flu is not dangerous to humans, just as horses do not succumb to our human coughs and colds. Treatment is supportive care including soft feed, cleaning of the nose, anti-inflammatory drugs such as phenylbutazone.

What can I do to prevent my horse from getting influenza?
Risk factors for catching equine influenza include a young age, and frequent mixing with new horses. The vaccine for equine influenza is not entirely protective and outbreaks of the disease are occurring with increased frequency worldwide despite the widespread use of vaccines. This is due to the infection being viral and therefore infection actually existing inside the horses’ own cell. However vaccinated horses have far less severe clinical signs, spread fewer viruses and are less likely to affect other horses. In addition equine influenza virus, while it can change its strain, does so far less readily than human influenza virus. Vaccines containing a particular strain therefore tend to stay protective. This saves us the unenviable task of trying to guess what strains to include in each year’s vaccine!

The vaccine can be administered from 5 months of age. The Jockey Club and FEI (The international governing body for all international equine events other than thoroughbred racing) have rigid guidelines for influenza vaccination times). After the initial vaccine a 2nd vaccination is due 21 to 92 days after. A third vaccine must be administered 150-215 days after the second. Then yearly boosters must be administered at less than 365 days. If a vaccine is even one day late then the course must be re-started. As of January 2005 onwards, influenza vaccination for all horses competing in FEI competitions require a vaccination within six months + 21 days of the competition. Therefore, if horses compete at FEI competitions then booster vaccines must be carried out at 6 monthly intervals.

I have an old pony and he never goes anywhere, does he still need to be vaccinated?
In short, the answer is yes. All horses are prone to tetanus since it can enter any wound and cause disease. Remember it often the small puncture wounds that are the most risky for trapping the bacterium in. As for protecting against flu, as I mentioned the vaccine is not completely protective and your horse may contract the disease but vaccination would ensure the clinical signs are not as severe as in an unvaccinated horse. Older horses are always prone to more severe disease than younger animals. That said if your horse does not compete anymore there is no legal requirement that the vaccinations have to be completed within the year. However, it is important to note that the duration of protection is usually less than a year for most horses so as the end of the year approaches your horse can become more vulnerable to infection. For this reason, if the vaccination due date has lapsed more than one month over the year I would strongly recommend restarting with the primary course of jabs. Should you have any further questions regarding vaccinating your horse please do not hesitate to call us.