Biology Reference
In-Depth Information
Chapter 18
The Endocrine System
The system of glands that secrete hormones is the endocrine system.
Hormones are chemicals that produce an effect on another part of the
body. Some hormones have very specific functions, while others affect
many other body systems in a subtle manner.
There are many different hormones produced throughout a cat's
body, but there are only a few that cause common imbalances or prob-
lems. Hormones are usually transported through the blood to their tar-
get tissues. The main endocrine glands that produce hormones are the
pituitary, thyroid, parathyroid, pancreas, adrenals and ovaries or testes.
IF YOUR CAT HAS A HYPER THYROID
Cats have two thyroid glands located on their lower neck. A normal
thyroid gland is difficult to palpate during a physical exam but may be
detected if it is enlarged. Hyperthyroidism is the most common
endocrine abnormality seen in cats. This condition is usually caused
by a benign growth, known as a thyroid adenoma, that overproduces
thyroid hormone.
Cats nine years old and up are most affected by hyperthyroidism.
While it is common for cats to be hyperthyroid, it is common for dogs
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