EDIT: Complete forgot about "vo-" (undo) for "cure". Another way to say "cure" in context to poison is "voviidost" (undo-poison - antivenin).

Alternate translation: "Pah viidost piraak vo-viidost, nuz dov piraak kinzon jotte." (All poisons have cures, but dragons have sharp maws.)

"Pah viidost aal kos qahnaaraan, nuz ni dov piraak (kinzon) jotte."

Direct translation is "All poison may be defeated, but all dragons have (sharp) maws."

I've distilled "cure" into "something that defeats the sickness/poison", and dragon teeth are in their maws. I added "sharp" to further point to (pun unintended) their teeth. Note: there's no need to pluralize poison to "viidostte" since the singular form can be understood as plural. As for "dragon poison", I'm sure blood loss could count as poison that drains your health slowly --especially when there's such a status effect in-game anyway!