
Laminitis a devastating and common ailment of the horse recognized
for centuries but even to this day we struggle with its treatment
and prevention.
What is Laminitis?
Laminitis is a very painful condition of the foot. Basically it
is a failure of the attachment of the pedal bone and the inner
hoof wall. The pedal bone is attached to the hoof wall by two
interlocking layers of laminae (strong connecting tissues) and
when these tissues for whatever reason get inflamed or the blood
supply is disturbed the attachment between the laminae fail. This
results in a tearing of the pedal bone away from the hoof wall
and due to the strong pull of the deep digital flexor tendon a
consequent rotation of the pedal bone within the hoof. This cascade
of events can result in varying degrees of change depending on
the inciting cause with worst cases involving the pedal bone rotating
so much as to have its tip penetrate the solar surface or the
attachment tearing away not only at the front of the foot but
all the way around allowing the pedal bone to sink within the
hoof.
What are the signs?
Laminitis can occur in two forms acute and chronic. In acute cases
the onset of signs is rapid and can be severe. In chronic cases
the symptoms can develop over time or may result from previous
acute attacks that fail to heal completely.

Acute cases:
Extreme lameness and unwillingness to move forward usually present
in the front feet but can be present in all four. Characteristic
stance with the forelimbs extended in front with the hind limbs
brought forward in an attempt to shift the weight back off the
front limbs, as they are usually worst affected. Heat in the feet
with a pronounced increase in the digital pulses. The horse may
be unwilling to lift either front foot off the ground. Painful
response when pressure is applied to the sole in front of the
frog. Swelling at the coronet may be present.
Chronic cases:
These cases will show most of the acute signs but not as pronounced.
The horse may appear stiff. Rings in the hoof wall may be present
with the rings being wider at the heel than at the toe. Bruising
of the soles may be present. On examination of the sole it may
appear to have a flat or dropped appearance. Some ponies that
suffer from chronic laminitis often have a large thickened neck
crest. "Seedy Toe" may be present where there is widening
of the white line at the toe with possible secondary infection.

What are the causes
of laminitis?
Many "triggers" of laminitis have been identified. The
most common cause is the sudden ingestion of an excessive amount
of soluble carbohydrates. This is where the horse engorges itself
on a lush pasture or breaks into the feed shed and helps itself
to the grain. Obese or overweight horses that have little exercise
are very vulnerable. Excessive concussion on a hard surface has
also been implicated. Laminitis can be a rapid sequel to toxic
conditions such as retained placenta or Salmonella enteritis.
Older horses that develop Cushing's disease, a hormonal disorder
have an increased susceptibility to the condition. Hypothyroidism
can also be a predisposing factor in its development. Excessive
weight bearing in one limb due to severe lameness in the other
may result in the good limb developing laminitis. Therapies using
corticosteroids can cause laminitis.
If you suspect laminitis what should
you do?
When your horse first suffers a laminitis attack, it is very important
to respond quickly. Early signs of laminitis can quickly escalate
to become quite serious. If you suspect laminitis contact your
veterinarian immediately. Put your horse in a deep-bedded stable
so that it has a good cushion under its feet. It is not advisable
to walk your horse as the laminae are torn, fragile and you risk
doing further damage. Your vet will then assess the case and investigate
if there is any underlying cause that needs immediate treatment
such as a retained placenta. If grain overload is involved your
vet may administer liquid paraffin. Initially the focus will be
on pain relief as laminitis is a very painful condition. Various
other anti-toxic drugs will be administered and drugs that improve
the circulation to the feet. Radiographs may be taken to assess
if rotation has occurred. Often the veterinary surgeon will liaise
with the farrier and special shoes to support the foot will be
applied. In the recovery period it may be necessary to repeat
X-rays and reassess shoeing at later stages. Recovery from laminitis
is a slow process and it should be considered in months and years
not days or weeks. Patience and diligent aftercare are therefore
very important in the treatment. Cases that do recover may be
prone to further laminitic episodes. It must also be said that
although most cases are usually treatable, laminitis has the potential
to result in permanent severe lameness making euthanasia the only
option.
When can the horse be ridden again?
Most horses that have been treated for laminitis can be ridden
again. After the pain is gone you will be dealing with a very
delicate foot. When you can start riding again depends on how
severe the symptoms were and how good the treatment response has
been. If there is any rotation it will take at least eight months
for the damaged areas to grow out. If no rotation has occurred
two months rest and correction of the predisposing factors should
be considered. Your vet should direct you when it is safe to start
riding again. Also once a horse has laminitis they are prone to
recurrences so it is important to watch closely for the signs
of laminitis and stop riding if you are suspicious.
How can you prevent laminitis?
Weight control is very important in the overweight pony. Restrict
access to lush pastures. It should be possible to fence the pony
into a small area of the paddock. Make sure feed sheds are closed
securely. Riding your horse daily is very important. Regular visits
from your farrier to maintain a well-balanced foot. Nutritional
supplements such as biotin supplements should be given if the
hoof quality is poor. A thorough knowledge of the causes of laminitis
is important so you can identify the risk factors early and thus
avoid them.
Herbal supplements as an aid to treating laminitis. Many owners
have found tremendous benefit in using herbal supplements in the
recovery of laminitic cases. Anicripple from the Animal Herb Company
is one I use regularly and find it an excellent adjunct to therapy.
In Chinese medical understanding of laminitis they see stagnation
of blood and energy in the feet, blockage of the channels and
toxicity as being important in the development of the condition.
Herbs such as Lonicera and Forysthia are included in the formula,
which have anti-infection and anti-toxic properties. Clematis
that opens the channels, Carthamus and Dang Kuei that helps nourish
and move the blood. Also pain-killing herbs are included. Thus
it can be a powerful remedy with many properties that can aid
healing. With recognition of the symptoms and causes of laminitis
and prompt action when you suspect it, the devastating effects
of this horrible condition should be minimized.
|