Laminitis
Veterinary Advice for Young
Riders.
The George Veterinary Group
Equine Clinic
Laminitis
ti
ven
e
r
P
mi
a
L
ng
2.
3.
4.
5.
6.
Welcome to the 6th edition of The George Veterinary Group Equine Clinic’s Young Rider
supplement. In this edition we are focussing on laminitis.
Whilst this is a much talked about subject there are some new thoughts, ideas and therapies
worth knowing about. Laminitis is not just a disease of little fat ponies. All shapes and sizes
can be at risk. As with any disease, prevention is always the aim.
Linda Belton BVSc MRCVS
is
nit
1.
Monitor your horse’s bodyweight using a weigh tape. Take
action to reduce body weight as soon as your horse exceeds his
target weight.
Regular exercise is vital. This is not only to help control body
weight but also for the beneficial effects of exercise on insulin
resistance.
Ensure your horse’s feet are kept regularly trimmed and well balanced.
Avoid high carbohydrate diets. This may be in the form of cereal
based feeds or spring grass that is high in sugars.
Be aware of the early signs of laminitis and seek veterinary advice straight away if you have any concerns. Laminitis should be
regarded as a medical emergency.
Treat any underlying condition that may be the cause of the laminitis.
Laminitis is a very painful condition of the foot. It results from disruption
of normal blood flow to the foot causing inflammation which can lead to
weakening of the structures in the hoof. These laminae are responsible
for supporting the pedal bone within the hoof and when they become
inflamed and weakened, the pedal bone can rotate or sink downwards.
It can eventually come
through the sole.
Laminitis varies in its
severity. In acute laminitis, symptoms appear
quickly and are severe.
In chronic cases the
symptoms appear
gradually over time and
are usually relapses
from previous acute
episodes.
Symptoms of acute
laminitis include;
•
reluctance to move and lameness (often
in more than one leg),
•
a very characteristic stance with the weight
shifted to the hind limbs
and the forelimbs
stretched out in front,
•
a strong pulse palpable on the pastern and side of the fetlock and hot
feet.
•
The lameness is exacerbated when
the horse is turned in circles or
walked on a hard surface.
In chronic cases of laminitis, rings in the
hoof wall may be seen. These rings are
wider at the heel than the toe as the hoof
grows faster at the heel than at the toe due
to the damage caused by bouts of laminitis.
This also is the reason chronic laminitics
tend to have an “Aladdin’s Slipper” shape to
the hoof. The soles of the feet tend to become flat or dropped and there may be
bruising evident. Widening of the
white line and a tendency to
s
the development of foot
Sign
abscesses is also seen.
Got a veterinary query?
Visit our vet archives online @
georgevetgroup.co.uk
Treatmen
t
Exact tre
atm
ture, seve ent will depend o
n
rity and a
ny underl the naof the lam
y
in
in
Regular
farriery
to
keep
your
horse’s
feet
y
usually a itis. Som e basic p g cause
pply to all
rinciples
ier
trimmed and well balanced is crucial to both the
r
r
cases.
• Rem
a
o
v
e
h
prevention
and
treatment
of
laminitis.
In
cases
of
o
rs
F
e fr
• Prov
ide stablin om grass.
acute laminitis where the attachments of the pedal bone
g with a d
bed.
eep ined
are weakened it is vital to support the bony column of
ible
• Institu
te
appropria
the foot and reduce the risk
te dietary
ment.
m anageof rotation or sinking. This
• Prov
id
e
p
a
can be done in a variety of
in relief a
nd anti in
ries.
flammato
ways.
• T rea
t
any unde
Frog supports can be banrlying cau
priate.
s
e
as appro
daged in place as an
• Fit fr
og suppo
emergency measrts.
ure and then we
use imprint first aid
glue on shoes subsequently.
As well as fitting the shoe, it is vital that the foot is correctly
trimmed first, ideally with the benefit of foot x-rays. As well as being able
to assess the degree of any rotation or sinking of the pedal bone, foot xrays with external markers allow for precise foot trimming and placement
of the shoe to achieve maximum support and comfort for the horse.
More information about imprint therapeutic shoes can be found on their
web site www.imprintshoes.co.uk.
There are a
number of supplements on
the market
aimed at preventing laminitis. As with
most things,
the answer to
the problem does not lie in a tub!
None of these products negate the need for
good preventative management as described earlier.
There are some supplements that do have
some science and logic behind their use
and are worth considering. A useful preventative product that has been around for
some time is Founderguard. This contains
an antibiotic called virginiamycin which acts
to maintain a healthy gut flora. This is important in controlling digestive processes
which if upset e.g. by the intake of too much
high sugar spring grass, can result in toxins
being absorbed from the gut and triggering
laminitis. Hippo – EX – Laminitis is another
product aiming to improve intestinal digestion. It contains a peptide which binds to the
excess sugar molecules thus helping to
maintain the normal gut flora. The use of
pro-biotics is also useful for similar reasons.
Inhe
ri
ted C
There has been some research
ondi
done on a herd of wild ponies which has protion?
vided evidence that there may be a genetic predisposition to developing laminitis. While it is not a simple inheritance it is an area worth keeping an eye on. Laminitis is a distressing and painful condition for an affected
horse. The last thing any of us would want to do is
knowingly breed a horse or pony likely to suffer from
laminitis.
C
This is now a well recogrome
d
n
y
sS
nised condition that can be
g
n
i
us h
the underlying cause of recurrent laminitis despite good dietary management.
Affected horses have a high circulating level of corticosteroid in the body. This occurs due to changes in
the pituitary gland at the base of the brain. The pituitary
is involved in regulating the body’s hormone balance
and in particular in controlling the production of corticosteroid via the adrenal gland.
In Cushings disease a tumour known as an adenoma
grows in the pituitary and it is hormonally active resulting in over stimulation of the adrenal gland and thus
increased levels of corticosteroid production. High levels of corticosteroid in the body have a number of deleterious effects, one of which is laminitis. Thus affected
horses have a tendency to chronic recurrent laminitis.
Cushings is usually only seen in horses or
ponies over 15 years old and there is an
argument that much of the change in the
pituitary gland is in fact age related and if
horses live long enough they will all eventually develop Cushings syndrome.
This may also explain why Cushings is
more commonly seen in ponies than
horses as they tend to live longer.
Other external
signs that may
alert you to a
potential problem with Cushings in your
horse include
increased
thirst, poor
coat change
with a long hairy coat that classically may
become curly, bulging fat pads above the
eyes (as opposed to hollows), sweating,
lethargy, a change in body shape with a
pendulous abdomen, dental and foot infections.
Cushings can be diagnosed by blood tests
and treatment is available that is safe and
effective. It is lifelong and acts to reduce
the level of circulating cortisol in the body
and thus overtime the consequential effects of the cortisol also subside.
EMS
Do you have a native
pony?
Fat on just fresh air?
Can’t lose weight?
Equin
e Me
Syndr tabolic
o me
If you have an overweight native
pony who lives on fresh air but loses
weight with great difficultly, then they may have a
relatively newly recognised disease called Equine
Metabolic Syndrome (EMS).
? Does your pony have any of these signs ?
•
• Obesity
Abnormal fat distribution over the body
usty
Thickened cr
neck
Fatty
shou
lders
Fat aro
und he
ad
of tail
atty
by , f
Flab eath
sh
Pot-bellied look
Hungry all the time
Lethargic and lazy
• “Good doer”
• Unexplained laminitis
Infertile or abnormal cycle in mares
•
•
•
It is now thought that EMS occurs as a result of evolutionary developments that have enabled native breeds
to survive harsh winters with food shortages. In the
wild, ponies are programmed to put on weight during
the warmer months when food is readily available; fat is
laid down in the abdomen and then gradually used up
over the winter months. Domestication has shifted this
balance because these ponies are now fed through the
winter and do not suffer any food shortage, therefore
they maintain their over-fat state throughout the year.
The fat cells (adipocytes) in the abdomen are now known to actively produce hormones which help to
control and regulate a number of body processes. In particular they are involved in generating a rise
in cortisol (steroid) levels. This steroid is critical in inhibiting the action of insulin – which controls
blood glucose levels. This system works well when the ponies DO lose weight over winter, since the
state of insulin resistance will be reversed, but many ponies enter the winter overweight, they maintain this level of condition and so the insulin resistance is NOT reversed. Long term, there will be too
much sugar in the blood which leads to a direct risk of laminitis developing.
Previously EMS was termed “peripheral Cushing’s disease” but this is misleading since there is nothing wrong with either the pituitary or adrenal glands as there is with Cushing’s disease. EMS can be
very hard to recognise because the signs are often subtle and can be confused with Cushing’s.
There is no single blood test to diagnose EMS. Glucose and insulin blood levels are useful and ponies with EMS test negative for Cushing's disease. Treatment revolves principally around increased
exercise to help with both weight loss and insulin sensitivity. A fitter horse, even if still overweight will
have an increased sensitivity to insulin and thus a lower blood glucose level. A human medication
used in type II diabetes can be helpful. Metformin is given orally and further increases insulin sensitivity. Nothing however changes the need for exercise, something we probably accept as good for all
of us!