Red Flags:

Advertise in classified newspaper ads, flyers in stores and on classified sites on the Internet?

Use hand painted "roadside" signs to advertise puppies or other pets for sale?

Advertise "Puppies always available" or "Puppies Ready for Christmas / Easter / etc.?"

Advertise many different breeds for sale?

Advertise oddball or specialized varieties or "rare" breeds?

Offer to meet you at a parking lot or public place to sell you the pup?

Sell puppies at a public place like a dog auction, flea market, yard sale, swap meet or pet store, or out of the back of a pickup truck, car, or van?

Tell you that the "whole deal" can be completed with one phone call or email?

Make excuses why you can't meet the parents of the pups?

Tell you that the parents of the pups are a different location and he's just acting as an "agent" to sell the puppies?

Offer stud service to the general public or sells "breeding pair?"

Tell you that he doesn't require spaying/neutering of "pet quality" puppies?

Try to sell you a puppy that is under eight weeks old?

Appear dirty, poorly groomed or have poor coat quality?

Act aggressive, vicious, anti-social or overly fearful?

Spend their lives in stacked cages or poorly lit outbuildings, garages or basements?

Lack shelter protected from inclement weather or kept from getting too hot or too cold?

Have no water available or water that is available is dirty or frozen?

Appear either too thin or too heavy or just seem generally unhealthy?

Seem to be more numerous than the breeder can properly care for, exercise and socialize?

Try to imply "quality" of the dog because he / she is "registered" or has "papers?" (See What Does Breed Registration Really Mean?)

Have suspended AKC registration privileges? Check here: http://www.barkbytes.com/suspend/suspindx.htm

Tell you that "Papers" are not available at time of delivery of the pup? (Please see: http://www.akc.org/reg/about.cfm for the full American Kennel Club explanation of their Registry and why this is a "red flag.")

Use registries like American Canine Association, Continental Kennel Club Inc. or others you have never heard of? (For more on the topic of breed registries, and a list of questionable breed registries, please see the "Chosing a Good Breeder" section of the "They're All Keepers!" website.)

Does the breeder demand cash only payment and/or does not have a State of Wisconsin Seller's Permit?

Has the breeder been the subject of complaints registered with local humane societies or sheriff's departments?

Has the breeder been convicted of a crime against animals (In Wisconsin, see http://wcca.wicourts.gov/index.xsl.)?