First of all American bulldog breeder that strives to be a quality breeder:

Takes responsible care of all of his or her American bulldogs breeding stock & puppies, and provides:
a) Companionship, affection, interaction & attention.
b) Nutritious quality dog food & fresh clean water.
c) Immunization.
d) Proper vet care.
e) Parasite prevention/treatment.
f) Grooming.
g) Exercise.
h) Socialization.

Certainly a reputable American bulldog breeder:

belongs to a national (and/or local) breed club and abides by their breed club’s Code of Ethics – American Bulldog Registery and Archives (ABRA)-
*Tests their breeding stock for any congenital diseases, conditions (ie: hip dysplasia, Von Willebrand’s Disease, retinal dyslasia, etc.), consequently strives to eliminate genetic problems by breeding only sound dogs (shown to be free of any serious physical conditions and/or temperament problems).
*Only breeds dogs that have excellent temperaments and as a result contributes to the whole breed.
* Above all is very knowledgeable about their breed.
* Most noteworthy strives to better their breed by every action.

Finally a reputable American bulldog breeder :

*Immunizes their puppies’ Sires and Dams (& their Puppies) against: Distemper, Hepatitis, Parvo, Parainfluenza, Corona & Rabies because vaccinations are your insurance that you receive a healthy puppy.
*Screens potential owners thoroughly, and does not sell to those who are unsuitable for the reason that puppies end up in stable household and are not given away to the pound.
*Educates potential owners, and discloses  information about their breed and as a result buyer is fully prepared for the puppy ownership.
*Has a spay & neuter contract or alters dogs prior to sale for the reason that American bulldogs stay pure and responsibly bred.
*Above all offers new puppy owners guidance and support for the puppy’s entire lifetime.
*NEVER sells puppies to puppy brokers, pet shops or puppy outlets of any kind including so-called “Kennel Clubs”.
*Shows, trials and/or titles their dogs in order to continue with their program excellence.
*Supports or participates in breed rescue work whenever possible and as a result contributes to the whole community
*In contrast to puppy mills responsible breeder never breeds out of greed and never over-breeds.
*Will take back a puppy or dog at any time because they stand behind their puppies.
*A reputable American Bulldog breeder wants to know as much about you, your household, your schedule and your ability to properly care for a puppy (throughout its entire lifetime), as you want to know about the breeder’s puppies.

Do your research before you purchase an American Bulldog Puppy.