It usually starts small. The cat who used to greet you at the door now sleeps through it. The one who cleared the counter in a single leap now hesitates. A coat that's lost its shine. A cat quietly going off her food — or bringing meals back up.
Different owners, different worries — and almost always the same shrug from everyone around them: “She's just getting older.”
But what if these scattered, unrelated-looking problems trace back to one missing nutrient?