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A DNA test for CaniAne Leukocyte Adhesion Deficiency (CLAD)
What is CLAD?
Canine Leukocyte Adhesion Deficiency (CLAD) is an inherited abnormality of the
immune system where the white blood cells are unable to fight infection. This disease
was first identified in 1975 in Irish Setters. Several animals displaying various forms
of recurrent infectious and immunological complications were found to have an aberrant
expression of a crucial aspect of white blood cell function. The identification of
the gene mutation responsible for the disease in Irish Setters was ascertained in
mutational analysis of that function in Irish Setter CLAD pedigrees.
From this, a single mutation was identified which showed complete association
with the disorder in Irish Setters. This mutation is thought to be responsible
for incomplete disulphide bonding within the ß-integrin protein, causing
defects in its function and hence an inadequate immune function.
Affected puppies are often, but not always, comparatively small and slow to develop.
They show infections from a very early age - umbilical infection at birth, tonsillitis,
sores on the body and accidental wounds or scratches that will not heal. Between 8 and
14 weeks there can be inflammation of the gums, which become red and swollen. Most
puppies get swollen joints with the bone beside the joint thickening and affecting
movement, making the dog unsteady until finally the animal is unable to stand up.
Affected puppies seem to be sore all over their body. The lower jaw becomes wider,
due to bone deposits and they have difficulty in opening their mouths. Their
temperature is raised and they seem to sleep more than usual. Puppies will
not necessarily have all of these symptoms at one time. The complications of
CLAD will lead to death.
There is no treatment for CLAD. Only the negative effects of the disorder
(the infections and inflammations) can be suppressed in order to maintain an
acceptable quality of life for the affected animals as long as possible.
Sooner or later the recurrent infections will become fatal.
A DNA test for CLAD
Breeds at risk
Breeding policy
Testing for CLAD
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