Basic HTML Version
A R T H R I T I S
SPRING 2012 ISSUE
EQUINE MATTERS
6
When you call out a veterinary surgeon to
look at your horse your vet will start with a
thorough physical examination and gait
analysis. This may involve trotting your horse
in a straight line and possibly being lunged
on a firm and soft surface. Sometimes a
ridden assessment is invaluable to identify
more complex problems. It may be
necessary that this examination is continued
at a dedicated equine clinic if the facilities
on your yard are not suitable for a thorough
lameness investigation.
On the basis of this examination your vet
may try to determine the exact location of
the lameness by injecting local anaesthetic
within a specific joint. If this joint is causing
the horse discomfort the local anaesthetic
will abolish the pain. At the next trot-up the
horse should appear sound.
Once the location of the lameness is found,
it will be necessary to assess the structural
damage to the joint. Traditionally, this will
be done by obtaining radiographs (x-rays) of
the affected joint (as shown in Figures 2 and
3). However, not all affected joints will show
radiographic changes, and not all joints
with radiographic changes have problems.
Fortunately other means of imaging are
available and sometimes your vet may
decide that your horse needs one or more
of the following investigations:
●
Ultrasonography
●
Scintigraphy (bone scan) (Figure 4)
●
Magnetic Resonance Imaging (MRI)
●
Computerised Tomography (CT)
●
Arthroscopy (keyhole joint surgery)
How do you know which joint(s)?
Figure 2:
Osteoarthritis of the pastern joint. Note new bone formation and collapse of joint
space due to loss of cartilage
Figure 3:
Osteoarthritis of the distal hock joints (spavin)
Treatment
Treatment greatly depends on what joint is
affected and the severity of the damage.
Generally the joint itself may be injected with
an anti-inflammatory such as corticosteroids
and artificial joint fluid such as hyaluronic acid.
Other intra-articular injections such as IRAP
®
could be a good alternative to steroids.
This will harness the regenerative and
anti-inflammatory properties of the horse's own
blood cells encouraging tissues to heal. Then,
following a period of box rest, your vet will
recommend an ascending exercise plan,
outlining exactly what your horse can and can't
do. Furthermore it will often involve a course
of phenylbutazone ('bute') or equivalent.
Other systemic treatments, such as an
intravenous infusion with tiludronic acid
(Equidronate
®
) or intramuscular injections of
polysulphated glycosaminoglycans (Adequan
®
,
Carthrophen
®
) can be prescribed tailored to
your horse’s needs. Some horses need a one-off
treatment, whilst others may require more
frequent injections. Remedial shoeing could also
be of benefit, and if so your veterinary surgeon
will discuss this with your farrier. The use of joint
supplements is also advocated in arthritis and
your veterinary surgeon will help you to make
the right choice for your horse.
Occasionally surgery is considered in cases
where there is no clear indication of what the
cause of lameness is. Keyhole surgery
(arthroscopy) can then be invaluable in
assessing the cartilage for any damage, and
treating it at the same time. In the case of
septic arthritis, seeking urgent veterinary
treatment will be vital for a good outcome.
Generally the joint will have to be flushed (joint
lavage), and any foreign material (gravel,
blackthorns) removed with your horse under
general anaesthesia. Aftercare will involve a
course of intravenous antibiotics, and frequent
bandage changes.
Prognosis
The prognosis is dependent on the severity of
the damage to the joint and the response to
medication. It is very difficult to predict how
your horse will respond to the treatment, and
what level of exercise your horse will be able
to attain. Quite often, with the help of a
balanced exercise routine, medication and rest
as appropriate, it will be possible to get the
horse back to the same level of exercise.
Figure 4:
Bone scan showing a hot spot in
the hock