my 3 yr. old 15 lb yorkie getting tests done to see if he has cushings or
a liver problem,his enzmye test indicate they are high,my question is how
do you know?
There are two tests commonly used in the initial diagnosis of Cushing's. The
ACTH stimulation test shows the response of the adrenals to injected
stimulating hormone. In Cushinoid animals there is extreme elevation in ***
Cortisol levels with this test.
The second test is Low Dose Dexamethasone suppression(LDDS) test. In normal
dogs, a negative feedback mechanism suppresses the release of stimulating
hormone from the pituitary when the circulating levels of cortisol reach a
certain point. With the LDDS test there is no change in the production of
cortisol when low doses of glucocorticoid are injected.
Once the diagnosis has been made with these tests, it is considered necessary
to differentiate between the two types of Cushing's. Pituitary dependant means
there is too much stimulating hormone being produced. This is usually due to a
Pituitary tumor, but fortunately is the less common. Non-Pituitary dependant
means there is a tumor on the adrenal that isn't regulated by the negative
feedback mechanism. The two types are differentiated using a high dose
dexamethasone suppression test.
In addition, radiographs or ultrasound are often used if an adrenal tumor is
8. lyme disease
11. horners disease