Also known as chronic adrenal
insufficiency, is a rare endocrine disorder in which the adrenal glands do not
produce enough steroid hormones (glucocorticoids and often mineralocorticoids)
and may occur as the result of many underlying causes. The condition is
generally diagnosed with blood tests, medical imaging and additional
investigations. Treatment involves
replacement of the hormones. If the disease is caused by an underlying problem,
it may be possible to address that.
This disease has
symptoms that are common to many other ailments, making diagnosis or results in
mis-diagnosis. But once Addisonís is correctly diagnosed, a properly treated
dog can live a normal, active life.
Addisons has been diagnosed in several
dogs in the last few years and is sadly creeping up in its numbers,
unfortunately there are currently no tests to see if breeding dogs carry this
disease. This is why DNA testing dogs now is important, even if all our dogs are
coming back clear, because in the future a test may exist for diseases like
Addisons, and we may be able to test all dogs, even historical dogs, thanks to
There are three forms of Addisonís
disease: primary, secondary and atypical. Primary and atypical Addisonís are
usually the result of immune mediated damage to the glands. Secondary
hypoadrenocorticism is from failure of the pituitary to stimulate the adrenals
with adrenocorticotropic hormone (ACTH). It is important for you to know which
type of Addisonís disease your dog is being treated for.
All causes in this
category are genetic, and generally very rare. These include
mutations to the SF1
congenital adrenal hypoplasia (AHC)
due to DAX-1 gene mutations and mutations to the
ACTH receptor gene (or related
genes, such as in the
Triple A or Allgrove syndrome).
DAX-1 mutations may cluster in a syndrome with
glycerol kinase deficiency with
a number of other symptoms when DAX-1 is deleted together
with a number of other genes.
To form cortisol, the
adrenal gland requires
cholesterol, which is then
converted biochemically into steroid hormones. Interruptions in
the delivery of cholesterol include
Smith-Lemli-Opitz syndrome and
Of the synthesis
congenital adrenal hyperplasia
is the most common (in various forms:
lipod CAH due to deficiency of
mitochondrial DNA mutations.
Some medications interfere with steroid synthesis enzymes (e.g.
ketoconazole), while others
accelerate the normal breakdown of hormones by the
can be a cause of Addison's disease.
Autoimmune destruction of the
adrenal cortex (often due to
antibodies against the enzyme
21-Hydroxylase) is a common
cause of Addison's in teenagers and adults. This may be isolated
or in the context of
autoimmune polyendocrine syndrome
(APS type 1 or 2).
Adrenal destruction is
also a feature of
adrenoleukodystrophy (ALD), and
when the adrenal glands are involved in
metastasis (seeding of
cancer cells from elsewhere in
the body, especially
hemorrhage (e.g. in
of abnormal protein in
Initially, the dog may be listless, or
seem depressed. Many dogs are described as just seeming off, or losing the
normal sparkle in their eye. Lack of appetite is a good indicator. Other
symptoms include gastro-intestinal problems like vomiting and diarrhea. Pain in
the hindquarters, or generalized muscle weakness such as a dog that canít jump
onto the bed or couch as he has done in the past is not uncommon. Shivering or
muscle tremors may also be present. The most important thing to remember is
that you know your dog better than anyone. If something seems amiss, have it
Dogs with Addisons
disease generally need to stay on medication for the rest of their lives.
There are many
holistic therapies you can consider, too many to list here and so I will point
where the majority of this information has come from. They are very nice people
and incredibly supportive. There website is full of information as well as a