Feline hypothyroidism is thyroid deficiency. It is rare in cats. It most commonly occurs after operations on the thyroid gland or treatment for hyperthyroidism. It is a dysfunction of the thyroid gland, which is in the cat’s neck.
An inadequate amount of thyroid is produced by the gland. The prefix “hypo” in medical terms means “low, under, beneath, down, below normal”1. The suffix, “-ism” means, “condition of, practice of, theory of”2.The deficiency of the thyroid hormone “impairs new hair growth and prolongs the resting phase”5. The resting phase of hair growth is called the “telogen” phase3. Hair growth is not continuous.
This causes a gradual thinning of the coat and makes it look dull.
In addition the cat might be lethargic, be constipated, gain weight, have brittle hair, be constipated, have excessive thirst4 and be mentally dull.
Another sign that the cat might exhibit is a type of dwarfism in which the head is enlarged with a short neck and legs.
Feline hypothyroidism is diagnosed through a blood test.
Treatment consists of daily hormone replacement therapy. This has to be carefully gauged as too much can result in hyperthyroidism4.
3. The Cat, Its behavior, Nutrition & Health
5. Cat Owner’s Home Veterinary Handbook page 111.