When to Transition a Puppy to Adult Food (and How to Do It)
Written by: Richard Rowlands
Your puppy has spent months growing, playing, and learning — burning through energy at an impressive rate. But as they approach adulthood, their nutritional needs shift, and it’s time to consider switching from puppy food to adult dog food. This transition has to do with more than just age, and correct timing is necessary to properly support your pup’s long-term health. Making the switch too soon can deprive them of vital nutrients, while waiting too long could lead to unnecessary weight gain. So, how do you know if your puppy is ready for adult food? And how can you ensure the change is smooth and stress-free? Grab your furry little buddy, and let’s take a look at what should be in their bowl.
Why Puppy Food Is Different from Adult Food
Puppy food is formulated to fuel rapid growth and development. It contains higher levels of protein, fat, and essential mineral nutrients like calcium and phosphorus — ingredients that support strong bones, muscles, and energy levels. As your puppy matures, their metabolism slows down, and they no longer need the calorie-dense nutrition designed for their early life stages. Transitioning to adult food at the right time helps maintain a healthy weight while ensuring your playful pal still receives balanced nutrition.
Related: The Top 10 Myths About Pet Food and Nutrition
When to Transition Your Puppy to Adult Dog Food
Once puppies have reached 80% of their adult size, they’re ready to transition to an adult diet. They’ll reach this size after about a year for most breeds, although smaller breeds (think Dachshunds and Jack Russell Terriers or any dog whose adult weight is typically less than 20lbs) will typically get there after about nine months. Larger breeds will take longer to reach 80% of their full size, with the very largest breeds taking up to sixteen months to get there. Because of this, these large dog varieties usually need extra time on a puppy-specific diet to support healthy development.
Refer to these guidelines when transitioning from puppy to adult food:
- Small breeds (under 20 lbs. adult weight): Typically ready for adult food around 9–12 months.
- Medium breeds (20–50 lbs. adult weight): Usually transition around 12 months.
- Large breeds (50+ lbs. adult weight): May need 12–16 months before switching.
- Giant breeds (over 100 lbs. adult weight): Often require up to 18–24 months on a large-breed puppy formula before transitioning.
Breed size not only affects when you transition and the portion size you serve, but also the nutritional composition your dog needs in their food. Look for breed-specific food formulas, especially for large and small breeds, to make sure your pup is getting the nutrition their body needs to stay strong and healthy.
How to Transition Your Puppy’s Diet Safely
Don’t rush! A sudden switch in foods can upset your puppy’s digestive system, so it’s best to introduce the new diet gradually over a week or two. Start with a mix of 10% adult food and 90% puppy and slowly change the ratio. If your furry family member responds badly to the change in their diet at any point (with an upset stomach, listlessness, loose stools, loss of appetite, or weight loss) you can adjust the mix back in favor of the puppy formula and give their stomach more time to adjust.
Watch for These Signs of Trouble
While most puppies adjust well, keep an eye out for any red flags:
- Diarrhea or constipation may indicate the new food isn’t agreeing with them
- Loss of appetite or excessive begging can signal the portion size needs adjustment
- Lethargy or unusual behavior may mean the diet isn’t providing enough nutrients
If you notice any persistent issues, consult your veterinarian to ensure your puppy’s nutritional needs are being met.
Final Tips for a Smooth Transition
- Stick to a schedule: Puppies thrive on routine, so keep mealtimes consistent
- Choose high-quality food: Look for an adult formula that meets AAFCO standards and suits your dog’s breed and activity level
- Portion control matters: Adjust serving sizes based on your puppy’s weight and energy levels to prevent overfeeding
By making the transition gradually and paying attention to your puppy’s needs, you’ll help set them up for a lifetime of healthy eating habits.
For meals that are as delicious as they are nutritious, explore Only Natural Pet’s full catalog of natural dog food options.
