Robson Vets
Equine Newsletter
Summer 2015
Vaccination
As some of you will have already experienced, we have changed vaccine
brands at Robson Vets. The new vaccine, Proteq, is the only vaccine currently
on the market which contains the recommended OIE strains of equine
influenza and as such, we feel this will offer the best protection for your
animal. Even if your horse does not attend competitions, we recommend ‘flu
vaccination for any animal in livery or at shared facilities.
Tetanus vaccination is important for all horses and ponies. The bacteria which
cause the disease are present in soil everywhere and horses appear
particularly susceptible to the disease. Any superficial cut is enough to allow
entry of the infection and production of the toxin, especially puncture wounds
or where the wound is contaminated.
The infection attacks the nerves controlling the muscles of the body and as
the disease progresses the individual will become stiff, have difficulty moving
and eating and eventually collapse and in the majority of cases, die. Bright
lights and loud noises can exacerbate the condition. Often the third eyelid will
protrude, the tail will be held out straight and their face may have an anxious
expression, due to muscle spasms in the head. Treatment is extremely
difficult and is aimed at removing any infection, so reducing the amount of
toxin produced. The disease can be prevented by a course of vaccinations
which are boosted every 2-3 years.
Choke
This is a relatively common problem seen in horses and ponies and is
typically caused by obstruction of the oesophagus (food pipe) with food;
occasionally a foreign body can be involved (wood or plastic, or evey whole
apples!). Fortunately, many cases of choke resolve quickly and spontaneously
and only cases in which the obstruction lasts for longer than 30 mintues are
likely to require veterinary assistance. Unlike in humans, horse with choke
CAN STILL BREATHE.
Clinical signs include: difficulty or repeated attempts at swallowing, stretching
or arching of the neck, coughing, food and saliva coming from the nose,
drooling, disinterest in food.
Diagnosis is usually reached on the basis of the clinical signs and can be
confirmed by passing a stomach tube up one nostril and into the oesophagus
– failure to reach the stomach indicates an obstruction. However, the nasal
cavity is very sensitive and it is not unusual to cause a nosebleed when
passing a tube; although it may look dramatic it is rarely a serious
complication.
Treatment usually involves a mild sedative and muscle relaxant to reduce
anxiety, relax the oesophagus and drop the head, reducing the risk of the
horse inhaling food and saliva. Occasionally, this will be sufficient to relieve
the choke, if not, attempts to flush the impaction gently away with warm water
may be needed. Very occasionally, more intensive treatment for longer lasting
or non-responsive chokes may be required at a referral centre.
To attempt to prevent choke, ensure sugar beet is well soaked and moisten
any pelleted food, add chaff to feed to slow down eating and encourage
chewing and saliva production. Ensure all your horses get a dental
examination at least once a year.
Most importantly – DON’T PANIC! Most cases will resolve spontaneously but
if things aren’t settling within 30 minutes, call the vet and remove all food to
prevent your horse or pony eating and worsening the obstruction.
Ragwort poisoning
Ragwort is a very common (though less so now) plant with yellow flowers
often seen growing on rough land and on roadside verges. It can also be
found on pasture, particularly on overgrazed and ‘starvation’ paddocks. When
it is growing it is unpalatable to horses, but when wilted or dried in hay it loses
its bitter taste and will readily be eaten but retains its toxic properties. These
toxins damage the liver, unfortunately, signs are often only seen months or
years after the plants were eaten. The liver can continue to function normally
until at least half of it is damaged; this means that damage will usually be
advanced before signs are seen.
Clinical signs are varied and non-specific but can include jaundice (yellow
gums and eyes), depression, weight loss, poor appetite, low grade colic with
or without diarrhoea, oedema (fluid swelling in the legs and under the belly),
photosensitization (pink areas of skin become red and blistered with normal
levels of light) and behavioural signs such as disorientation, circling and
pressing their head to the wall.
There is no specific treatment or cure to the disease or that will reverse the
damage done to the liver. All treatment is aimed at reducing the work the liver
must do and other supportive therapies. Response to treatment can be seen if
the disease is diagnosed early. A good diet, with low levels of good quality
easily digestible protein is important to prevent the overproduction of
ammonia. Vitamin supplementation can be helpful but should be done with
care as high levels of iron, vitamin A and others can further damage the liver.
Milk thistle has been shown to support liver function.