Sixty-four dogs were shown to have hyperadrenocorticism. Seven dogs had an adrenal gland tumor removed at laparotomy. Twenty-six dogs were diagnosed as having pituitary-dependent hyperadrenocorticism. At necropsy, 16 of these 26 dogs had a pituitary tumor and bilateral adrenal gland hyperplasia and 10 had bilateral adrenal gland hyperplasia without evidence of a pituitary tumor. Thirty-one dogs were diagnosed as having hyperadrenocorticism after complete remission of all clinical signs following o,p'-DDD therapy. Each of the 64 dogs was tested by ACTH stimulation and by dexamethasone suppression to assess the pituitary-adrenal axis prior to surgery, necropsy, or treatment with o,p'-DDD (mitotane). The dexamethasone screening test was diagnostic more often than was the ACTH stimulation test in each of the 3 groups, ie, 100% vs 57% in the adrenal gland tumor group, 96% vs 88% in the pituitary-dependent hyperadrenocorticism group, 86% vs 84% in the dogs that responded to o,p'-DDD therapy, and 92% vs 83% in all 64 dogs. No dog with hyperadrenocorticism was normal on both endocrine tests. The response to dexamethasone administration in the adrenal gland tumor and pituitary-dependent groups of dogs with hyperadrenocorticism was similar. Significant differences were not seen in the response to ACTH stimulation in these 2 groups of dogs with hyperadrenocorticism. Either of these tests suggest hyperadrenocorticism if results are abnormal but do not provide evidence for differentiating between pituitary-dependent and adrenal gland tumor hyperadrenocorticism. Both tests were considered useful and reasonably reliable when attempting to confirm a diagnosis of hyperadrenocorticism.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of the American Veterinary Medical Association|
|State||Published - 1983|
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