WELSH SPRINGER SPANIEL JOINT HEALTH GROUP
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Secretary: Mrs Julie Revill
Furzelands Farm
Langford
Maldon, Essex
CM9 4SZ
Tel: 01621
854765
Email: Julita@furzelands.demon.co.uk
Chairman: Dr Jeff Sampson BSC.DPhil.
Treasurer: Anne Morgan
Committee: N of E WSSC – Delegates: Suzanne Backhouse, Lisa
Butler
Trustee: Suzanne Backhouse
SEWSSC Delegates: Julie Revill, Stephen Pick
Reserve Delegate: George Isherwood
Trustee:
WSSC Delegates:
Reserve Delegate: Sue Connolly
Trustee:
WSSC of SW Delegates:
Jan Janes,
Reserve Delegate: Debbie Roberts
Trustee: Annie Glover
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DISEASES AFFECTING THE WELSH
SPRINGER SPANIEL
FACT SHEET 3 – GLAUCOMA
WHAT IS GLAUCOMA?
Glaucoma
is an increase in fluid inside the eye, which leads to damage to delicate
structures within the eye
which may eventually lead to blindness,
following swelling of the eye. In its
acute form glaucoma is painful, but in all types it is the effect on sight
through destruction of the optic nerve that represents its most important
feature. Two forms of glaucoma are
considered to be inherited in the dog: open-angle glaucoma (very uncommon in
the dog) and angle-closure glaucoma. The
latter form is considered to be inherited in the Welsh Springer
Spaniel. In angle-closure
glaucoma Goniodysgenesis (characterized by non-differentiation of the pectinate
ligament and a narrowed drainage angle) predisposes the patient to acute onset
disease, usually in middle-age.
WHAT TREATMENT
IS AVAILABLE?
Treatment is often unrewarding but if the pressure can
be kept within normal limits, the progression of the condition may be halted
for considerable periods. Medical
treatment, in the form of eye drops applied daily, is usually the first choice
but surgical procedures are also available.
These procedures are aimed at increasing the outflow of fluid from the eye,
but there may be complications which require further surgery. Research continues into appropriate and
successful methods of controlling this distressing condition.
IS GLAUCOMA
INHERITED?
There is some evidence to suggest dominant
inheritance, from a paper by Doctor Keith Barnett, and Beverley Cottrell of
1988. The Joint Health Group initiated
an investigation into the incidence of pre-disposition in the Welsh Springer
Spaniel in 1996 and 100 to 150 dogs were tested by Doctors Keith Barnett, Ian
Mason and Beverley Cottrell, the object being to ascertain information about
the incidence of abnormal drainage angle anatomy in our breed. It is apparent that there is a breed
incidence of glaucoma in the Welsh Springer Spaniel
and this problem is linked to abnormal drainage angles formation. Work in other breeds has shown that abnormal drainage
anatomy is inherited and that severe forms of abnormality predispose to
glaucoma development.
CAN MY DOG BE
TESTED FOR THIS CONDITION?
Yes.
Fortunately, the goniodysgenesis can be identified at an early age by
gonioscopy, and as such predisposed animals can be screened out of breeding
programmes. Contact should be made with
an Eye Specialist, via your own Veterinary Surgeon in the first instance. A few drops of local anaesthetic are applied
to the corneas of the eyes to be examined and then a special type of contact
lens is applied to the eye, permitting examination of the drainage angle of the
eye, with either an ophthalmoscope or a camera.
The problem facing breeders and eye panellists is that
we cannot at the moment predict with any certainty what degree of
Goniodysgenesis places a dog at significant risk of developing clinical
disease. The eye test allows only two
categories – pass or fail. An objective method
of assessing the angle is difficult and has led to apparent
inconsistencies. The object of the investigations
under way is to arrive at a practical consistent method of diagnosis and to be
able to give rational breeding advice.
To put this into perspective there are very few known
cases of Glaucoma currently in the Welsh Springer Spaniel, and it is very easy
to have your dog tested for the condition as early as 6 months of age, when, if
the animal is found to be pre-disposed, a decision can be made not to breed
from it, which may help to reduce the incidence of the condition in the
breed. It should be pointed out here
that the pre-disposition DOES NOT MEAN that your dog will develop Glaucoma, in
fact it really is quite unlikely bearing in mind the numbers currently known in
the breed. However, it is known that
pre-disposed animals may pass the condition on to their pups. It should be pointed out that a pass DOES NOT
MEAN your dog will NOT develop glaucoma.
ANATOMY OF THE EYE AND THE
DRAINAGE ANGLE
The drainage angle (or iridocorneal
angle) is formed by the iris and cornea.
Aqueous (the fluid inside the eye) is produced at a constant rate, and
in a healthy eye drains out through this angle into the veins around the eye. In the normal eye, production and drainage of
fluid occur at the same rate, keeping a constant pressure inside the eye. In the dog, abnormality of the pectinate ligament (which spans the angle) can lead to
impaired drainage. This leads
to an increase in pressure, as aqueous continues to be formed at the same
rate. This abnormality
can be detected by looking at the drainage angle through a goniolens,
and is termed goniodysgenesis.
(Beverley Cottrell 2010)
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Other fact sheets are produced by the WSS Joint Health Group.
Contact the
Secretary for further information.
Dated: June 2011
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