Guide
American Bully Growth Chart
Month by month from eight weeks to two years, what a normal curve looks like, and when to stop worrying that a puppy has stalled.
An American Bully reaches most of its adult height between twelve and eighteen months, then keeps filling out in width and mass until two to three years. Growth isn’t linear: it comes in bursts with flat periods between, and a puppy that seems to have stopped for three weeks is usually about to grow.
Month by month
| Age | Standard | XL | What is happening | |
|---|---|---|---|---|
| 8 weeks | 6 to 10 lb | 10 to 15 lb | 14 to 20 lb | Leaving the litter. Four meals a day |
| 3 months | 11 to 17 lb | 18 to 26 lb | 24 to 34 lb | Fast growth. Socialisation window still open |
| 4 months | 15 to 23 lb | 25 to 36 lb | 33 to 46 lb | Teething. Chewing peaks |
| 6 months | 22 to 34 lb | 36 to 52 lb | 48 to 68 lb | Growth begins to slow. Still no forced exercise |
| 9 months | 27 to 44 lb | 45 to 66 lb | 62 to 88 lb | Height nearly done. Looks lanky and unfinished |
| 12 months | 30 to 50 lb | 50 to 74 lb | 72 to 102 lb | Height largely complete. Width hasn’t caught up |
| 18 months | Adult | Adult | Near adult | Growth plates closing. Exercise restrictions lift |
| 2 to 3 years | — | — | Filling out | Chest and head finish. The adult dog arrives |
These are indicative and a healthy puppy can sit outside them. What matters far more than hitting a number is the shape of the curve and the condition of the dog. If your vet is happy with the body condition score, the figure on the scale isn’t the thing to worry about.
The lanky phase, which catches everybody out
Somewhere between nine and fifteen months your bully will look wrong. Leggy, narrow through the chest, head not yet filled in, nothing like the photographs that made you want one. Owners write to me at this stage convinced something has gone amiss.
Nothing has. Height finishes well before width does, so there’s a period of several months where the dog has reached its full frame and hasn’t yet built onto it. The chest and head are the last things to finish, often not until two or even three years old. Wait it out and resist the urge to feed the dog into looking better, which is the single most damaging response to this phase.
What to do while the plates are still open
The first eighteen months are when joint damage is easiest to cause and hardest to see, because the skeleton is soft and the dog is enthusiastic.
- No forced running. Not alongside a bike, not on a treadmill, not long distances. Free play at the puppy’s own pace is fine, because a puppy stops when it’s tired and a puppy on a lead beside a bicycle doesn’t.
- No repeated jumping down from furniture, out of a truck bed, off a deck.
- Carry it on stairs until six months, and put a runner on hard treads afterwards.
- Keep it lean. A fat puppy is carrying load its joints weren’t built for yet.
- Large-breed growth food for an XL, for the controlled calcium.
Ask your vet when they’re satisfied the growth plates have closed. It varies by dog and by class, and it’s the point at which the restrictions above stop applying.
Predicting an adult size
The best available predictor is the parents, not a chart. Ask any breeder what the dam and the sire measure at the withers and what they weigh, and you’ll get a far better estimate than any formula produces. Ask me and I’ll tell you, including when the honest answer is that a puppy is likely to finish smaller than you hoped.
Adult size by class · When growth actually stops · Portions by age
Ask what the parents measure
It’s a better predictor than any chart on the internet, and you’ll get a straight answer rather than the one that sells the puppy.