More than 4 or 5 litters a year.  Proceed with caution. You may be dealing with profit-motivated breeding program. Some small-scale commercial kennels are owned by reputable breeders that have a quality breeding program. Others may refer to themselves as "professional breeders". They operate small to medium size commercial kennels. The care their puppies receive is variable. The focus of these breeding programs is usually quantity not quality. 

• FYI: Some ethical breeders with well-established show or working lines may occasionally produce more than  litters in a year.

More than 2 different breeds of dogs, especially if the dam and littermates are not on the premise.  Proceed with caution. You may be dealing with a puppy broker. They often buy a litter of puppies at a discount for resale. They buy and sell many different kinds of purebred puppies. Some backyard breeders and small-scale commercial breeders are motivated by financial profits. They may deal with several different popular purebred dogs.

• Ethical breeders often concentrate on a single breed of dogs, but many reputable breeders have 2 breeds.  
• Responsible breeders never transfer their puppies to a middleman or a pet store for resale.

Both parents on the premises.  Proceed with caution. This arrangement sounds good to prospective owners, but it may be a sign of a backyard breeding program or a small-scale commercial breeder. These breeders find it convenient to own both the male and the female. They do not have to located a stud dog, transport their female to the stud dog, or pay the stud fee each time they want to breed. Often the sire and dam did not come from good quality breeding programs. Their dogs have not been carefully selected as breeding dogs based on the breed standards, pedigrees, health clearances, and other desirable qualities.

•  Please note: Some well-established reputable breeder have 2 or more unrelated lines on premises, so they may own both sire and dam of some of their litters. 

Beware of breeders that:

Do not obtain the recommended health clearance on their dogs. This is red flag! You are probably dealing with a backyard breeder, a puppy mill, or a puppy broker. The breeder may claim their local veterinarian says the dogs are okay and their lines does not produced affected offspring.

Do not issue American Kennel Club or Canadian Kennel Club registration papers with their puppies.  Another red flag! There are now several alternative canine registration organizations that may not be reputable. Some will issue papers for dogs that are not purebred. Many breeders that utilize alternative registration organizations have lost registration privileges with reputable organizations such as AKC. The breeder may not have AKC full registration because the dog was sold with AKC limited registration or without papers because the puppy's breeder did not consider the puppy to be breeding quality.

Do do not interview potential buyers. Red flag. Responsible breeders look for responsible dog owners, so they will ask about how you plan to care for a puppy. They will be available to help you resolve problems after the sale. Some of these breeders love their dog and just want to make a little extra money. Others think breeding a litter will be fun for the family or educational for the kids. They are unaware of the responsibilities involved in breeding purebred dogs and placing puppies in appropriate homes. Puppy brokers sell puppies bred by someone else to make a profit. Backyard breeders, commercial breeders,  and puppy brokers also do not take responsibility for their puppies when the new owners need advise or when the owners can no longer care for the dog.

FYI: Responsible breeders want to interview prospective owners so they can place their puppies in appropriate homes. Ethical breeders do not want their puppies to be bred indiscriminately and they do not want them to end up in an animal shelter. These breeders carefully place their puppies in approved homes with a spay/neuter agreement and limited registration.

Select the stud dog based primarily on geography.  Proceed with caution. Selection of a sire should be based on pedigree research and an evaluation of the conformation of both potential parents, not convenience. Temperament and working ability should also be considered. Typically, backyard breeders and small commercial breeders are not willing to travel very far from their home. These breeders usually do not know about breed standards, pedigrees, recommended health clearances, temperament concerns, and/or working ability.

Sell puppies for different prices based on gender, color, or registration papers.  Red flag. These practices are common among backyard breeders and home-based small commercial breeders. They offer a discount on the puppies sold without registration papers. They sometimes try to cash in on the most popular color. All pet quality puppies in the litter should be sold with AKC registration papers for the same price, regardless of color or gender.

FYI: Some reputable breeders sell pet quality puppies for less than show quality puppies. Their pet quality puppies are usually sold with a spay/neuter agreement and an application for AKC limited registration.

Promote white, silver, champagne, and charcoal Labradors.  Another red flag.  There are 3 recognized coat colors in Labradors- black, yellow, and chocolate. Pale yellow Labradors are sometimes advertised as "rare white Labradors" but there are no white Labradors. Their coat is just a light shade of yellow. The dark fox red coloring is another acceptable shade of yellow. Silver, champagne, and charcoal Labradors are not colors recognized by AKC.  These dogs have 2 dilute genes at the D chromosome site that result in an abnormal color. The introduction of the dilute d gene in Labradors was probably a result of crossbreeding a chocolate Labrador with a Weimaraners in the mid 1900's. Silver, charcoal, and champagne Labrador puppies are not more valuable and sometimes lines that carry the dilute d gene are associated with poor quality puppies.