Puppy feeding and growth
When do giant breed puppies stop growing?
Last updated 23 September 2026 · How we write and check this
Short answer
Giant breeds, generally those expected to exceed 45 kg (99 lb) as adults, typically stop growing somewhere between 18 and 24 months, making them the slowest maturing size category. Some individual giant breeds can continue very gradual filling out even beyond two years.
The longest puppyhood of any size category
While a small breed is often fully grown before its first birthday, a giant breed puppy is frequently still gaining meaningful weight and muscle mass well into its second year, which is why feeding plans and growth tracking need to extend much further for these breeds.
Height versus overall fill
Height at the shoulder for a giant breed often stabilizes somewhat earlier than total body weight and muscle mass, meaning a giant breed dog can look close to full size well before it has actually finished developing, which is why weight, not just visual height, should guide when to consider it fully grown.
Confirming the finish line
Monthly weigh ins from around 15 to 18 months onward, with growth having genuinely flattened across three consecutive checks, is the most reliable way to confirm a giant breed dog has finished growing before switching it to an adult maintenance food.
Key takeaways
- Giant breeds typically stop growing between 18 and 24 months, the slowest of any size category.
- Height often stabilizes before total weight and muscle mass finish developing.
- A giant breed dog can look fully grown well before it actually is.
- Confirm growth has stopped with several consecutive flat monthly weigh ins.