Back
INHERITED
IMMUNODEFICIENCY DISEASES IN DOGS AND CATS First broadcast on www.provet.co.uk
|
This information is provided by
Provet for educational purposes only.
You should seek the advice of your
veterinarian if your pet is ill as only he or she can correctly advise on the
diagnosis and recommend the treatment that is most appropriate for your pet.
Several inherited immunodeficiency
diseases have been reported to occur in animals as well as in humans The
following congenital diseases cause immunodeficiency :
- Canine Leucocyte Adhesion Deficiency
/ Canine Granulocytopathy Syndrome
Canine granulocytopathy syndrome (now called
canine leucocyte adehesion deficiency) has been reported to be an inherited
autosomal recessive trait in Irish Setters and the condition has been
reviewed recently in a report (Trowald-Wigh G. et al Journal of Small
Animal Practice (2000) Vol41 p211-217).
With this disorder neutrophils have impaired
phagocytosis and have impaired ability to kill bacteria due to lack of
adhesion proteins (integrins CD11b/CD18, b2-integrins).
Deficiency of these proteins prevents leucocytes from leaving blood vessels
- so poor numbers are found in tissues even though large numbers are present
in the blood - and renders them unable to phagocytose bacteria opsonised by
fragment C3b.
The age of onset of problems is 2-4 months
and clinical signs reported include :
- Post-natal infection of the umbilicus
(called omphalophlebitis)
- Inappetance (anorexia)
- Gingivitis
- Lymph node enlargement
- High white blood cell (neutrophil) count.
Over 200,000mm3 has been
reported.
- Metaphyseal osteodystrophy - radius and
ulna
- Craniomandibular osteopathy
- Osteomyelitis
- Respiratory disease including
interstitial pneumonia
- Poorly healing skin wounds
These cases are difficult to treat and most
animals are euthanased before they are 6 months of age.
Chediak-Higashi Syndrome is caused by giant
lysosomes forming in cells - including leucocytes. It has been reported to
occur in blue Persian cats, Hereford cattle and other species. Clinical
signs include :
- Dilution of hair colour
- Albinism (coat and iris)
- Photophobia
- Haemorrhages - due to abnormal platelets.
- Increased susceptibility to infection -
due to impaired chemotaxis, and reduced hexose monophosphate activity.
In blue Persians the coat becomes lighter,
the iris changes colour from copper or gold to yellow/light green and the
retina loses pigment. Congenital cataracts may be present.
- Combined Immunodeficiency
Combined B-cell and T-cell immunodeficiency
is extremely serious and life-threatening. Combined immunodeficiency has
been reported in long-haired dachshunds and in basset hounds. Clinical
signs
- Severe respiratory tract infections
- Premature death
- Complement (C3) Deficiency
Complement fragment C3b is an opsonin which
coats bacteria surfaces rendering them susceptible to phagocytosis. C3
deficiency results in affected individuals being unable to opsonize
bacteria, making affected individuals susceptible to severe bacteraemias.
Complement C3 deficiency has been reported to be an autosomal recessive
trait in Brittany Spaniels. C3 concentrations in heterozygotes are about 50%
of the normal amount, but individuals do not show clinical signs. Homozygous
individuals have C3 concentrations of only 0.003% normal and show
typical signs of immunodeficiency with bacterial infections, septicaemia,
and death. Clostridia and gram-negative bacteria are usually involved.
- Cyclic Haematopoiesis of Grey Collies
This is a cyclic disorder of the bone marrow
resulting in low neutrophil counts, and these neutrophils also have impaired
bactericidal activity due to altered intracellular biochemical activity
including reduced myeloperoxidase activity and impaired iodination of
ingested protein . The precise mechanism that causes this disorder is not
known but it is an autosomal recessive trait.
Clinical signs include :
- Severe, recurrent bacterial infections
- Haemorrhages - due to low platelet counts
- Respiratory infections
- Gastrointestinal infections
- Infection of the umbilicus
- Death - neonatal or within 3 years.
Affected animals can be successfully treated
with a normal bone marrow transplant and lithium carbonate has been reported
to be a successful treatment restoring cell counts to normal ....but it must
be given continually.
- Growth hormone deficiency
Immunodeficiency has been reported in a litter Weimaraners which were
deficient in growth hormone and had low T-cell lymphocytes. Clinical signs
included :
- Recurrent severe infections
- Poor growth rate and condition
Treatment with bovine growth hormone was successful.
A line of German
Shepherd Dogs have also been reported to have a this disorder and it is
an autosomal recessive inherited defect.
A genetic defect resulting in IgA deficiency has been reported to occur in
Beagles, Shar Peis and German Shepherd Dogs..
Clinical signs include :
- Recurrent respiratory tract infections (eg Bordatella bronchiseptica)
- Dermatitis (staphylococcal infections, demodex)
- Parvovirus infection (despite vaccination)
- Seizures
- Bacterial overgrowth in the intestine of German Shepherd Dogs ?
The defect occurs because in affected individuals B-cell lymphocytes fail
to develop into plasma cells which synthesise and secrete IgA.
- Lethal Acrodermatitis in Bull Terriers
In affected individuals impaired T-cell function results from an
autosomal recessive trait for abnormal zinc absorption and metabolism. The
zinc deficiency and immunodeficiency causes a variety of signs :
- Dilution of coat colour
- Recurrent respiratory tract infections
- Skin disease - footpad cracks, paronechia, dermatitis with
crusting of the feet and around mucocutaneous junctions.
This condition does not respond to zinc supplementation because the
animal can not absorb or utilise it properly and affected puppies die by 15
months of age.
In this condition the neutrophils and
eosinophils have round nuclei due to incomplete nuclear segmentation and
they may be described as "juvenile" on laboratory examination..
The disorder is an autosomal dominant trait that has been reported to occur
in foxhounds other dogs eg Basenji, and domestic short-haired cats.
Clinical signs include :
- Neonatal deaths
- Lower litter sizes surviving to weaning than normal dogs.
Updated October 2013
|