Feline hypothyroidism is no laughing matter

Driving along a busy road I saw an office window that caught my eye. It was a clean looking building with a long front window, and it's only sign was painted along the length of the window. It said "Feline Hypothyroid Treatment Center." I didn't know cats had a problem with hypothyroidism, and apparently, it's a big enough problem in my town to warrant an entire center devoted to treatment. My husband and I discussed whether this business was a front for drug racketeering or truly a treatment facility for this heinous disease. Ooooo, if only I owned a cat--maybe I could borrow one just to check it out. And how would I know if my cat had hypothyroidism? The symptoms are "lowered metabolic rate and general loss of vigor." Isn't that the definition of "Cat"? Lying around sleeping all day? I so don't understand this.