Addison's disease, also known as
hypoadrenocorticism, is not terribly common in dogs but can be potentially
devastating when it does occur.
What Causes
Addison's Disease
The adrenal glands, located next to
the kidneys, produce a variety of hormones including those that allow
animals to respond to stressful situations (glucocorticoids) and those
that maintain normal fluid and electrolyte levels in the body (mineralocorticoids).
When the adrenal glands do not produce adequate amounts of these hormones,
Addison's disease is the result. Usually, the dog's own immune
system has attacked and destroyed his adrenal tissues, causing Addison's
disease. Less frequently, other causes such as drug therapy are
responsible. For example, the sudden withdrawal of high doses
of corticosteroids (e.g., prednisone) may cause Addison's disease
in dogs.
The Signs of Addison's Disease
Any dog can develop Addison's disease,
but it is most frequently diagnosed in young to middle-aged females.
Typical symptoms include:
- vomiting
- diarrhea
- dehydration
- weakness
- increased thirst
- poor appetite
- weight loss
With severe Addison's disease, extremely
low glucocorticoid and mineralocorticoid production causes a condition
known as an Addisonian crisis. Affected dogs usually collapse,
have extremely slow and irregular heart rates, and may die.
Unfortunately, all of these symptoms
may be caused by a number of different diseases, and because Addison's
is relatively uncommon, it is frequently overlooked or misdiagnosed.
Routine blood work may hint at the
presence of Addison's disease, especially if an electrolyte panel
is included. Finding low sodium and high potassium in the blood
is suggestive, but other diseases can cause these results also.
To add to the confusion, some Addisonian dogs only suffer from low glucocorticoid
production and their normal mineralocorticoid levels mean that these
typical electrolyte changes do not occur.
An ACTH stimulation test is required
to definitively diagnose all cases of Addison's disease.
Veterinary and Home Care
Dogs in the midst of an Addisonian
crisis will need to be hospitalized for intravenous fluid therapy, glucocorticoid
injections, normalization of the body's electrolyte levels, and close
monitoring. Long-term therapy includes medications to replace the missing
mineralocorticoid and glucocorticoid hormones.
Options include:
fludrocortisone
acetate – an oral medication
that has good mineralocorticoid and some glucocorticoid activity.
Additional supplementation with glucocorticoids may or may not be necessary.
Percorten-V – an injection given about once every
25 days to replace natural mineralocorticoids. Additional supplementation
with glucocorticoids is necessary.
prednisone – a glucocorticoid that may be given at
low doses regularly and/or at higher doses at times of stress.
Addison's disease cannot be cured
but with a dedicated owner, affected dogs can live long and happy lives.
The above is provided for information purposes only and should not be used for the diagnosis or treatment of any condition.
This information does not cover all possible variables, conditions, reactions, or risks relating to any topic, medication, or product and should not
be considered complete. Certain product or medications may have risks and you should always consult your local veterinarian concerning the treatment of
your pet. Any trademarks are the property of their respective owners.