L-lysine treats are widely used by cat owners managing feline herpesvirus flare-ups and general immune support, and the format matters as much as the dose because a cat that refuses the treat gets nothing. We compared the chews and lickable treats owners ask about most, looking at lysine content per serving, palatability, and whether the ingredient list is clean enough for daily use. In our evaluation we relied on manufacturer specifications, the way lysine is commonly used in feline care, and aggregated owner feedback rather than fabricating our own testing. The honest caveat is that lysine’s benefit for herpesvirus is debated in the veterinary literature, so this is a conversation to have with your vet. These treats support immune health, they do not cure infections, and any cat with eye, nose, or breathing symptoms needs a proper exam. Use this guide to pick a palatable, well-labeled product once your vet agrees it is worth trying.

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