Disclaimer: The following is only general information. If you believe that your horse has a problem please call your veterinarian as soon as possible.
The importance of immunising your horse against some diseases cannot be overstated. Understanding the diseases that can be prevented or at least minimised through vaccination, is as important as understanding horse nutrition, providing a safe living environment, developing a worming programme, having a qualified farrier regularly attend to your horse’s hooves or getting an equine dentist to check your horse’s teeth annually.
These are all fundamental horse care issues.
Standard Vaccination Programme
There are no 'standard' vaccination programmes in Australia, UK or North America (USA and Canada). Each country, state, province or individual situation requires evaluation by your veterinarian.
The criteria that they will use are:
Risk of disease (anticipated exposure, environmental factors, geographic factors, age, breed, use and sex of the horse)
Consequences of the disease (death of the horse, loss of use, infectious to humans)
Effectiveness of the vaccination
Cost of immunisation (time, labour, and vaccine cost) versus the cost of the disease (time out of competition, impact of movement restrictions, labour, medication or loss of life)
The AVMA (American Veterinary Medical Association) as well as veterinary associations in other countries define 'core' vaccinations as ones that protect against diseases that are:
endemic to a region
a danger to public health
required by law
virulent, highly infectious
Core vaccines must demonstrate that they are safe and highly effective, in other words they must exhibit a high level of patient benefit versus a low level of patient risk to justify their use in the majority of patients.
Internationally the following 'core' vaccines meet these criteria:
Tetanus (every country)
Eastern & Western Equine Encephalomyelitis/EEE & WEE (North America, however other forms are named after their geographical location, such as, Venezuelan Equine Encephalomyelitis/VEE)
West Nile Virus/Encephalomyelitis (many countries)
Rabies (every country except Australia and New Zealand)
These vaccinations may be included in a vaccination programme after your veterinarian has undertaken a 'risk-benefit' analysis. This type of analysis is required because the prevalence of a particular disease may vary from country to country, region to region, or population to population. It may also vary between individual horses within a population.
Rotaviral Diarrhoea is common, highly contagious and extremely serious if left untreated.
Vaccines are available for the following diseases:
Anthrax (most countries)
Botulism (all countries)
Equine Herpesvirus/Rhinopneumonitis (most countries)
Equine Viral Arteritis (most countries)
Equine Influenza (all countries except Australia, New Zealand and Iceland)
Potomac Horse Fever (USA)
Rotaviral Diarrhoea (all countries)
Strangles (all countries, mainly young horses)
Many others are in development, such as vaccinations for Hendra and Nipah virus.
Note: It is important to consult your veterinarian to develop an immunisation programme that suits your region and circumstances.
Controlling Infectious Diseases
Apart from immunising your horse or horses, based on your veterinarian's advice, it is critical that you also put in place good management practices.
These should include:
Reducing exposure to infectious agents in your horse's environment
Identifying factors that decrease resistance or increase your horse's susceptibility
Contact with outside horses should be minimised when you travel to shows.
The following factors increase the chances of infection:
Population Density – Breeding facilities, sale yards, boarding stables, performance stables, competition stabling and racetracks all increase the risk of infectious disease transmission (particularly respiratory tract infection)
Movement of Horses – When you move horses on and off your property or have young horses living with older horses or introduce new horses without a quarantine period, you increase the risk
Environmental and Management Issues – Stress, over-crowding, parasites, poor nutrition, poor sanitation, contaminated water supply, existing illnesses, inadequate rodent, bird and insect control as well as the movement of people, equipment and vehicles on and off your property during times of contagious disease outbreaks will all increase the risk
Note: Mosquitoes, flies, ticks, fleas, other biting insects, various bats, rodents, birds and infected wildlife can all be vectors for various infectious diseases (a vector is an organism that transmits a disease from one animal to another). By controlling and/or minimising your horse's exposure to these vectors you will minimise the risk of your horse contracting the disease.
Minimising the Risk
Develop an immunisation programme with your veterinarian. Recognise that some vaccinations require several injections and maximum immunity is not instantaneous but may take several weeks. With this in mind, the immunisations will need to be given in advance of exposure to high-risk periods. Read and understand the manufacturer’s instructions regarding storage of vials, handling and the method of delivery (injection under the skin, into the muscle, into a vein or nasal spray), as well as the length of time before immunity.
Locations for intramuscular injections.
Address all environmental and management issues (see all the 'risk factors' described above)
Develop a biosecurity plan that includes a quarantine area on your property, where horses can be kept separate from other horses as well as other pets (dogs, cats, birds, etc).
Quarantine all new horses for at least two to three weeks – observe them, take their temperature every day at the same time, worm them and administer immunisations where necessary.
Immediately quarantine any horse that is showing any clinical signs of disease
Keep competing and travelling horses separate from horses that have not left your property
Do not put young horses in with older horses (which have a better developed immunity)
Immunise all horses in your herd at the same time. This not only simplifies record-keeping but also minimises the transmission of disease. It is also helpful if you have a horse that reacts badly to a particular vaccine by minimising the chances of exposing an unimmunised horse to the disease.
No vaccine will provide complete immunity, particularly at the time of an epidemic. Also, there is the potential for some horses to have an adverse reaction. This is extremely rare but it can happen.
Not all infectious diseases are contagious. For example a horse can't catch Tetanus directly from another horse, therefore Tetanus is infectious but not contagious. Strangles, on the other hand, is highly contagious and can be transmitted by body fluids.