Feline acromegaly: The keys to diagnosis
Caused by excessive growth hormone secretion, this likely underdiagnosed endocrinopathy may be lurking in your feline patients—especially older, poorly controlled diabetic males. Here's a look at which diagnostic tests can help you detect it.
|Oct 1, 2013
Similar to its etiology in people, acromegaly in cats is the result of a functional adenoma of the pituitary gland that releases excessive growth hormone despite negative feedback.1
ANATOMY AND PHYSIOLOGY Growth hormone is produced in an anterior lobe of the pituitary gland, specifically by cells called somatotrophs. The regulation of growth hormone is complex, and many factors—both environmental and endogenous—are responsible for its control. The two most important regulators of growth hormone production and release are growth hormone-releasing hormone (GHRH) and somatostatin, which are produced in the hypothalamus. While growth hormone release is stimulated by GHRH, it is inhibited by somatostatin as well as by negative feedback from itself and IGF-1.1
Feline acromegaly is an uncommon disease, although it is thought to be underdiagnosed. It most commonly affects middle-aged and older, male castrated cats. In one study, 13 of 14 cats with acromegaly were males, with an average age of 10.2 years.2 This association may be biased, however, as most cats in which acromegaly is diagnosed are presented for complications associated with diabetes mellitus, which is also common in older, male castrated cats. Based on available data, no known breed association for feline acromegaly exists.