How long does dry food stay fresh after opening?

Six weeks in a sealed container, away from heat and light. Here is the reasoning behind that answer, and the exceptions worth knowing.

The short answer

Six weeks in a sealed container, away from heat and light.

Kibble oxidizes once exposed to air. Keep it in the original bag inside an airtight bin, do not top up old food with new, and write the opening date on the bag.

Why it works that way

Feeding decisions compound: a 10% overshoot becomes 2–3 kg a year, and joint disease follows weight rather than age. That is why portion control and body condition scoring outrank brand loyalty in every credible feeding guideline.

• Weigh food rather than scooping by eye for at least two weeks.
• Score body condition monthly using ribs, waist and belly tuck.
• Change one variable at a time so you can tell what worked.

When to ask your vet instead

See a vet rather than adjusting diet if you notice weight loss without diet change, persistent loose stools, vomiting, or a sudden refusal to eat. Those are clinical signs, not feeding problems.

Adjust slowly, measure consistently, and let body condition be the referee.