HAS
YOUR HORSE BEEN VACCINATED?
We take a look at some of the most common infectious diseases in New Zealand
and the best course of action to help protect your horse through a good
immunisation programme.
Article written by SHNZ.
Salmonella, tetanus, strangles, equine herpes - these are some of the commonly known diseases in the horse world and well worth taking the time to immunise your horse against if you wish to enjoy a happy healthy horse for many years to come.
A
good immunisation programme will often start from foal age, with maintenance
boosters at regular intervals thereafter, which your vet will advise you
of. The process simply involves injecting certain bacteria or viruses
that are inactive into the horse - often two or more doses are required
to create an immune system response. These bacteria or viruses have been
modified so they avoid causing the actual disease in the horse but alert
the body to their presence. This sends the body into action to build up
the required protective antibodies in the bloodstream and create a guard
against infection. The reason maintenance booster shots are required at
regular intervals is because after awhile the built up antibodies start
to disappear and need to be "re-activated".
As with humans, vaccinating your horse against diseases does not guarantee total protection, in some cases vaccination will decrease the severity of the disease but still not completely prevent it.
Different horses will have different requirements with regards to what they should be vaccinated for - factors such as age, environment, use and general exposure to the diseases will be considered by your vet to determine the vaccination programme most suited to each individual horse.
Salmonella
This is a bacterial disease that more commonly affects young foals,
very old or immune deficient horses more commonly than mature healthy
horses. The disease's most obvious sign is severe diarrhoea, which can
lead to blood poisoning and sometimes even death. Horses appear depressed
with raised temperature and usually very obvious diarrhoea! Birds are
commonly infected with this disease. Treatment for horses is very intensive
and therefore can cost alot. Foals that survive a bout of salmonella may
continue to suffer ill thrift and scours.
Foals and broodmares are the best to vaccinate for Salmonella. Foal vaccination
can start at around 3 months old while broodmares require an annual booster
about 3 weeks prior to foaling (to also help protect the newly born foal).
Tetanus
Tetanus is a highly fatal and infectious disease caused by a bacteria
that enters the body through cuts and wounds (commonly a puncture of the
foot), or the umbilicus of a newborn foal. Because the spores live in
the soil and can last for years, tetanus is a constant threat to all horses
who are highly susceptible to the disease (as are their human companions!).
While it is not contagious from horse to horse, once infected, it is an
extremely difficult disease to treat. Muscle stiffness and spasms are
common symptoms, including muscles in the face which will prevent the
horse from eating or drinking properly (hence the name "lockjaw").
The legs also gradually stiffen and the horse may have an anxious expression,
with further symptoms arising as the disease progresses. Most horses
affected with tetanus will die so prevention through immunisation
is essential.
Foals should be given a tetanus injection when they are born and their
umbilical cord covered with iodine and antibiotic powder to help it heal
up and prevent any infection from their sudden exposure to the ground.
Foals can then be started on a lifetime tetanus immunisation programme
from around 3 months of age, and it is common practise to give broodmares
an annual booster before foaling to help protect the newborn foal. Anytime
your horse suffers a deep wound or foot injury, giving a tetanus injection
is also a wise idea as a protective measure.
Strangles
This is a highly contagious disease of the upper respiratory tract with
symptoms including fever, nasal discharge, low appetite and enlarged glands
around the throat and jaw. This can become very sore and cause difficulty
breathing, hence the term "strangles". Because of its extremely
contagious nature, horses diagnosed with strangles should be isolated
and a strict hygeine proceedure followed as it can be passed on via
hands, clothes etc. Unfortunately, due to differing strengths of this
disease, vaccination against strangles does not offer 100% protection,
however will decrease the severity and number of horses affected.
Foals can be first vaccinated for strangles at around 3 months of age,
while broodmares should be given their annual vaccination about
3 weeks before foaling.
Equine Herpes Virus
(EHV)
There are two major types of Equine Herpes virus found in New Zealand,
known as EVH-1 and EVH-4, which actually cause two different diseases.
While both types cause infection of the respiratory tract of the horse,
EVH-1 can also cause abortion in pregnant mares (usually between 7 months
to full term), foal death and paralysis of the hind and sometimes front
limbs. Horses with Equine Herpes may have discharge from the nose and
a cough, loss of appetite, fever and generally feel low and lethargic
(similar symptoms to the common cold or influenza). The infection can
remain hidden and show up when the horse undergoes stress etc, or be present
but remain inapparant in carrier animals, which is a reason why it can
go undetected and be passed on quite easily through horse populations
(the same as cold sores, the human herpes virus).
Equine herpes viruses are aerosol meaning tiny particles of dust or water
are inhaled and, due to their size, penetrate into the nasal passages
and even right into the lungs. This means the virus can be spread through
direct contact, contact with secretions or even sharing drinking water.
It is generally suggested that broodmares and stallions are vaccinated
for EVH-1, with young horses vaccinated for EVH-4 only if certain circumstances
seem necessary.
What To Do
As always, if you are in doubt about whether your horse has been vaccinated
or ever notice any symptoms in your horse that are worrying, call your
vet and get them to give your horse a checkover.
While vaccinations cannot always give 100% protection, they are worthwhile
and necessary in responsible horse management. Talk to your vet about
an immunisation programme for your horses and they will discuss the best
course of action for each individual.
Information for this article was sourced from the EBNZVA and "Veterinary Notes For Horse Owners". See Disclaimer