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Addison's Disease (Hypoadrenocorticism)
- Case 2
"Sarah Elizabeth" a 3 1/2 year old female Labrador Retriever was
presented with symptoms of vomiting, lethargy, and loss of appetite
of 3 days duration. On physical examination, Sarah Elizabeth was
found to be quite depressed and dehydrated, otherwise in good
physical condition. A plan was made to draw blood samples for
routine laboratory evaluation, but difficulty was met obtaining
blood due to partial collapse of her circulatory system. An
intravenous catheter was placed immediately and intravenous fluid
therapy initiated as well as systemic antibiotics. By the
time the blood results were back the following morning, Sarah
Elizabeth's condition had improved tremendously. This in itself was
highly suspicious of the hypovolemia and collapse characteristic of
hypoadrenocorticism or Addisons's Disease.
Laboratory
results were consistent with Addison's disease.
Blood results:
BUN (Blood urea nitrogen) 81 mg/dl (normal = 7-27 mg/dl)
Creatinine 2.1 mg/dl (normal = 0.4-1.8 mg/dl)
Sodium 131 meq/L (normal = 141-156 meq/L)
Potassium 6.5 meq/L (normal = 4.0-5.6 meq/L)
Sodium/Potassium ratio 20 (normal = 27-40)Based
on a presumptive diagnosis of Addison's Disease, an ACTH (adrenocorticotropic
hormone) test was performed. An initial blood sample was drawn and
.25 mg. of synthetic ACTH (Cortrosyn) was injected intramuscularly.
One hour later, another blood sample was drawn. These two samples
were then analyzed for blood cortisol, the natural secretion of the
adrenal glands. The first sample establishes the baseline level of
cortisol in the blood. The second sample measures the response of
the adrenal glands to stimulation by ACTH. A dog with normal adrenal
gland function will produce a large amount of cortisol after
stimulation with ACTH. A dog with Addison's disease will have a
depressed response. The ACTH stimulation
test results
were as follows:
Normal Sarah Elizabeth
Pre-ACTH
2-6 0.2
Post-ACTH
6-18 0.3
These results definitely confirm a diagnosis of
hypoadrenocorticism or Addison's Disease. Treatment was started with
a single injection of
Percortin-V
(desoxycorticosterone pivalate) at 1 mg per pound of body weight.
This injection is then repeated once a month. Percortin-V is a very
expensive medication, but much more consistent than the alternative
(Florinef-F). Once the patient is stabilized, we subsidize a large
portion of the expense. Our current (2005) charge to the client is
$1.50 per milligram. Sarah Elizabeth's monthly cost for Percorten-V
is $90. An oral dose of prednisolone was started at 10 mg once a
day. Follow-up blood panels have shown Sarah Elizabeth's
electrolytes (sodium and potassium) to have returned completely to
normal.
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