The Japanese Akita Club of Great Britain (proposed) make no representation, express or implied with regard to the accuracy of the information contained in this section and cannot accept any legal responsibility for any errors or omissions that may take place.
The information provided within this section is purely for the listing
of known diseases of The Japanese Akita-Inu and NOT FOR A MEANS OF DIAGNOSIS
AND/OR TREATMENT OF ANY ANIMAL.
Progressive Retinal Atrophy (PRA)
This is due to a defect or failure of the bodily defence mechanisms in which antibodies become active against some of the host’s own cells. An example is spontaneous auto-immune thyroiditis which occurs in dogs.
Auto-antibodies can be produced at any time by any individual, but in most they are eliminated by suppressor cells. However, auto-anti-bodies may persist if there is abnormal B-Cell activation, or T-cell dysfunction.
Immune-mediated diseases are of two kinds: Primary, an auto-immune reaction only against self; and secondary, a similar reaction occurring when viruses, tumours, parasites or drugs are involved.
Primary diseases are either organ-specific e,g Auto-immune haemolytic anaemia, or systemic e.g. Lupus Erythematosus, also Thrombocytopenia, polyarthritis , pemphigus.
Pemphigus covers a group of uncommon disorders that occur in dogs. With
these conditions, there is an abnormal immune response to normal components of
the skin, resulting in separation of cells. This leads to blisters, pustules,
and crusting erosions in the skin. There are some similarities to pemphigus in
humans, but many significant differences as well.
Breed predispositions are recognized for 2 forms - pemphigus foliaceus
and the milder pemphigus erythematosus.
It is advisable not to use
affected dogs in breeding programmes, even though inheritance for these
conditions has not been worked out.
It may
be related to Autoimmune Disease (with or without involvement of other parts of
the body). This, essentially, is when our immune system recognises a part of
our own body as foreign (albeit a small part, like one type of protein).
Trauma
to the eye, or even the other eye in the past, can lead to Uveitis. In many cases
the cause is said to be unknown. This may well mean that the Uveitis is of the
autoimmune type. The word “idiopathic” may often be used to describe this
group.
Another
important way of classifying the different types of Uveitis is by describing
the part of the eye that is affected. Very simply, there may be:
This
affects the front of the eye, normally the iris (iritis) or the ciliary body
(iridocyclitis). Iritis, strictly speaking is an older term for Anterior
Uveitis but is still used frequently. Iritis is by far the most common type of
Uveitis and also the most readily treated. Having said that, iritis is
something that needs quite close monitoring because complications such as
raised eye pressure and cataracts can occur.
This
affects the area just behind the ciliary body (pars plana) and also the most
forward edge of the retina (see the diagram above). This is the next most
common type of uveitis.
This is
when the inflammation affects the part of the uvea at the back of the eye, the
choroid. Often the retina is affected much more in this group. The choroid is
basically a layer rich in small blood vessels which supplies the retina.
Dogs that have experienced lens luxation should not be used for breeding.
However this condition often does not occur before 4 to 7 years of age, making
it difficult to identify affected dogs before they are used for breeding.
Animals of predisposed breeds should be screened for glaucoma before
being used for breeding. Affected dogs and their close relatives should not be
bred. Unfortunately, glaucoma does not generally become apparent until after
breeding age has been reached, usually 3 years of age or greater.
There are several forms of lupus erythematosus that are recognized in
people, two of which have been identified in dogs. Lupus is an autoimmune
disorder, meaning that the body mounts an inappropriate immune response to some
part of itself.
Systemic lupus erythematosus (SLE) is an uncommon but severe disorder in
which the inappropriate immune response is widespread in the body, and can
cause arthritis, kidney disease, anemia, and skin disease. Cutaneous lupus
erythematosus (CLE) is thought to be a milder variant of SLE, and the problems
are confined to the skin. CLE is also called discoid lupus erythematosus.
Although the mode of
inheritance is not known for either cutaneous or systemic lupus erythematosus,
these conditions run in families. Affected animals should not be bred and it is
prudent to avoid breeding their close relatives as well.
With this condition there is patchy loss of pigment in the skin
(leukoderma), particularly in the facial area. There may be whitening
(leukotrichia) or graying (poliosis) of the hair. It may be that the immune
system targets the melanocytes - the cells that produce pigment.
Various forms of
the above diseases are all manifestations of what is known in Japan as
Hokuto-Koyanagi-Harada syndrome and in the USA and Great Britian as
Vogt-Koyanagi-Harada syndrome VKH. The manifestation of these autoimmune
diseases depends largely on the hereditary preposition of the dogs as well as
some inciting cause that results in stress to the system. Some may be mildly affected while others are
quite severe. Aggressive treatment is
always necessary.
Also known as ‘Night Blindness’ this is a hereditary condition, where the blood vessels of the retina undergo progressive atrophy and the dog suffers from impaired vision in consequence. To endeavour to correct this the pupil dilates widely, even in daylight, and the dog’s expression become staring. At night or at dusk, the dog is unable to avoid objects and blunders into them, but during full daylight it appears to see quite well.
No treatment can arrest the progressive degeneration and the dog gradually becomes blind. In severe cases puppies may show first symptoms soon after weaning.
Neither dogs nor bitches which show the condition should be used for breeding.
There is a joint scheme in the UK operated by the British Veterinary Association and The Kennel Club to reduce the incidence of this disease in any breed of dog: and certificates are issued to dog-owners.
Thrombocytopenia means a reduction in platelets (thrombocytes).
Platelets (one of the cell types in the blood) play an important role in the
clotting process; thus the main result of a decrease in platelets is increased
bleeding - for example, nosebleeds.
In immune-mediated thrombocytopenia (IMT), the reduction happens because
there is increased destruction of platelets by the body's own immune system, at
a rate faster than they are produced in the bone marrow. IMT may be secondary
to some other process (such as an infection, tumour, or drug reaction) or it
may be primary, meaning that no other causative factor can be found. It is more
common in certain breeds, suggesting there is an inherited component. IMT may
occur by itself or with other conditions like systemic
lupus erythematosus and autoimmune
hemolytic anemia.
Dogs that have had an episode of primary immune-mediated
thrombocytopenia should not be used for breeding.
The clinical signs of hypothyroidism are caused by a decrease in normal
thyroid hormone activity. The disorder may be acquired (a progressive
deficiency of thyroid hormone) or congenital (meaning the animal is born with
the disorder). The acquired form is the most common disorder of the endocrine
system in dogs. It occurs as a result of gradual atrophy of the thyroid gland
or of gradual infiltration and replacement of the thyroid gland with
lymphocytes due to an autoimmune process (lymphocytic thyroiditis).
Acquired
hypothyroidism is generally seen in middle-aged (4 to 10 years) mid - to large
breed dogs. Congenital hypothyroidism is very rare.
Normally red blood cells live about 4 months in dogs. As the cells age,
they are removed and destroyed by other cells that are part of the immune
system. New red blood cells are produced in the bone marrow at a rate that
matches the destruction of older cells. In autoimmune hemolytic anemia, the
immune system destroys red blood cells prematurely, faster than the rate at
which new ones can be produced. The name says it all - anemia (reduced red
blood cells) caused by hemolysis (destruction) by the body's own immune system
(autoimmune).
Dogs who have been
diagnosed with AIHA should not be used for breeding, and it is preferable to
avoid breeding their close relatives as well.
Von Willebrand's disease (vWD) is a common, usually mild, inherited
bleeding disorder in people and in dogs. It is caused by a lack of von
Willebrand factor (vWF), which plays an essential role in the blood clotting
process.
Normally the body responds to an injury causing bleeding through a
complex defence system. This consists of local changes in the damaged blood
vessels, activation of blood cells called platelets, and the coagulation
process. A reduction in von Willebrand factor leads to abnormal platelet
function and prolonged bleeding times. Affected dogs are prone to bleeding
episodes such as nose bleeds, and generally experience increased bleeding with
trauma or a surgical procedure.
Three forms of the disease are distinguished based on vWF concentration
and function. Dogs with Type I vWD (by far the most common) have mild to
moderate bleeding abnormalities, depending on the level of vWF. The much rarer
types II and III vWD cause severe bleeding disorders.
This is a perplexing condition in which the sebaceous glands in the skin
become inflamed for unknown reasons, and are eventually destroyed. These glands
normally produce sebum, a fatty secretion that helps prevent drying of the
skin.
Although the
genetics have not been determined, the condition does appear to be inherited in
those breeds studied. It is thus preferable to avoid breeding affected dogs of
any breed, their siblings, and their parents.
Cutaneous asthenia is a group of conditions where there are various
underlying defects in the structure of collagen, the fibrous connective tissue
of the body. Dogs with cutaneous asthenia have abnormally stretchy and fragile
skin which tears easily, resulting in large wounds. Some dogs also have
looseness in the joints and abnormalities of the eye (lens luxation, cataracts).
With dominant forms of this disorder, affected dogs and the affected
parent should not be bred. If the inheritance appears to be recessive (ie. an
affected dog is born of apparently normal parents), then the parents (carriers
of the trait) and siblings (potential carriers) of the affected dog should not
be bred.
This term covers a number of abnormal conditions of the acetabulum and head of the femur.
Some of these conditions are hereditary. They include:
Subluxation, in which the head of the femur is no longer firmly seated within the acetabulum. Deformity of the head of the femur gradually develops. The symptoms include a reluctance to rise from the sitting position, and a swinging gait, observed when the puppy is 4 to 5 months old.
Slipped epiphysis This also causes pain and lameness at 4 to 6 months, but is difficult to distinguish from Subluxation.
Congenital dislocation, in which the acetabula are too shallow to retain the heads of the femurs in position.
The BVA and The Kennel Club jointly run a scheme whereby X-rays of a dog’s hip joint are examined by a panel of experts and given a score according to the condition of the joint. The intention is that dogs showing a tendency to dysplasia will not be used for breeding.