Short answer: The American Bully is a companion breed built for a heavily muscled look — the United Kennel Club recognized it on July 15, 2013, describing it as a “natural extension” of the American Pit Bull Terrier. The American Bully Kennel Club standard divides it into Pocket, Standard, Classic and XL varieties by height, and says there’s “no particular weight for the breed.” Its largest (XL) type is now restricted in the UK and Ireland.
The American Bully is a relatively young breed, developed specifically to be a muscular-looking but even-tempered companion — not a working or fighting dog. Understanding that intent matters for judging what one is actually like to own.
What Is an American Bully?
The UKC’s breed history says the American Bully “developed as a natural extension of the American Pit Bull Terrier,” with one type taking on “a specific build and structure” distinct enough to be recognized as its own breed. It lists the American Pit Bull Terrier, American Bulldog, English Bulldog and Olde English Bulldogge as breeds that influenced it. Breeders selected for a stocky, heavily muscled frame and a stable, people-focused temperament.
Two registries matter. The UKC recognized the breed on July 15, 2013, and the American Bully Kennel Club (ABKC) maintains the widely used four-variety size standard. The American Kennel Club does not register the breed. For how the American Bully differs from its ancestor, see American Bully vs Pitbull, and for the wider family of bull breeds, what “bully breed” actually means.
What Size Classes Does the American Bully Come In?
Varieties are set by adult height at the withers (and, for the Classic, by build), according to the ABKC standard:
| Variety | Males | Females | Build |
|---|---|---|---|
| 14 to under 17 in | 13 to under 16 in | Same heavy build as Standard, just shorter | |
| Standard | 17–20 in | 16–19 in | Heavily muscled, massive, bulky |
| Classic | 17–20 in | 16–19 in | Lighter bone and less overall mass |
| XL | Over 20 up to 23 in | Over 19 up to 22 in | Standard build, taller |
The UKC standard uses the same height bands, grouping Standard and Classic together. These are varieties within one breed, not separate breeds — an XL Bully and a Pocket Bully share the same standard and lineage. Neither standard sets a target weight; the ABKC says only that height and weight should be in proportion and dogs should never be obese. For the XL variety specifically, see our XL Bully size and legal status guide.
What Temperament Should You Expect?
The breed standards describe the ideal clearly. The UKC calls the American Bully “first and foremost, a companion” whose “demeanor is gentle and friendly,” and says “aggressive behavior towards humans is uncharacteristic of the breed, and highly undesirable,” listing viciousness and extreme shyness as disqualifications. The ABKC standard adds that dog aggression is also undesirable.
Those are goals breeders select toward, not guarantees about any individual dog. An American Bully’s strength means training and socialization aren’t optional extras: an under-socialized or poorly managed dog of this size and power is a much harder problem than a small breed with the same gap. Meet both parents, choose a breeder who can show you calm, sociable adult dogs, and start reward-based training and socialization early.
What Health Issues Should Owners Watch For?
We found little published health research specific to the American Bully, so be wary of confident breed-health statistics. What is documented:
- Exaggeration is a concern even to the breed’s own registry. The UKC warns that “quality is never to be sacrificed in favor of size and mass,” cautions judges against rewarding exaggerated dogs, and lists “overly massive dogs” and dwarfism as disqualifications.
- Heat risk rises with weight and a short muzzle. A 2020 VetCompass study of 905,543 UK dogs in Scientific Reports found that dogs with a brachycephalic skull shape, dogs over 50 kg and dogs heavier than their breed average were at greater risk of heat-related illness, which killed about 14% of affected dogs. Heavily built Bullies need shade, water and cool-hour exercise, especially in Indian summers.
- Joints and weight. As with any heavy, fast-growing dog, ask for hip and elbow screening results on both parents, feed a puppy food suited to large breeds (see why calcium matters for large-breed puppies), and keep adults lean.
- Deafness and albinism are disqualifications in the ABKC standard, so ask how breeders screen for them.
Where Is the American Bully Restricted?
- UK: The XL Bully type is a banned type. GOV.UK says it is a criminal offence in England and Wales to own one without a Certificate of Exemption; Scotland and Northern Ireland have equivalent schemes. Because the law judges a dog by its appearance, a dog at the top of the Standard height range can also be assessed against the official XL definition. Ear cropping, which the ABKC standard allows, is itself an offence in the UK under the Animal Welfare Act 2006, according to GOV.UK.
- Ireland: Importing, breeding, selling and rehoming XL Bully type dogs has been banned since October 1, 2024, and owning one without a Certificate of Exemption since February 1, 2025, according to Ireland’s Department of Agriculture.
- India: A 12 March 2024 central circular asking states to ban 23 breeds and their crosses was quashed by the Delhi High Court on 18 April 2024, which allowed the government to decide afresh after inviting objections. We found no replacement national rule; check state and municipal rules.
- US: There’s no nationwide ban, but some cities, counties, landlords and insurers restrict “pit bull-type” or bully breeds by appearance.
Laws in this area change quickly, so check the official source for your area before buying or traveling with a Bully.
What Should You Know Before Getting One?
- Ask breeders for hip and elbow screening on both parents, regardless of size class, and meet the parents
- Plan for real daily structure — training and socialization, not just exercise
- Check your homeowner’s or renter’s insurance and local housing rules before committing, since bully-type breeds are sometimes affected by breed-specific policies even when the individual dog has no history of issues
- If you live in or may move to the UK or Ireland, understand how the XL definition works before choosing a larger variety
- Budget for a large, strong dog’s lifetime food, vet and training costs
This article is for informational purposes only and does not replace guidance from your veterinarian or legal advice.
Sources
- United Kennel Club — American Bully breed standard (archived copy)
- American Bully Kennel Club — American Bully standard
- GOV.UK (Defra) — Rules for owning an XL Bully dog in England and Wales, updated September 2026
- GOV.UK (Defra) — XL Bully conformation standard, February 2024
- Department of Agriculture, Food and the Marine (Ireland) — Ban on XL Bully dogs, June 2025
- mygov.scot — XL Bully dogs in Scotland, July 2026
- nidirect — XL Bully dogs
- LiveLaw — Delhi High Court quashes Centre’s circular banning sale and breeding of “dangerous & ferocious dogs”, April 2024
- Deccan Herald (PTI) — Karnataka HC overturns ban on ‘ferocious dogs’, issues directives to Centre, April 2024
- Hall EJ et al., Scientific Reports — Incidence and risk factors for heat-related illness (heatstroke) in UK dogs under primary veterinary care in 2016, 2020
