Whether or not this disgruntled customer has a claim depends on whether or not your wife is a licensed breeder. If so, she may be liable under the Texas Deceptive Trade Practices Act. This act protects consumers from relying on false representations from sales persons, but it requires the consumer to allege and prove that they were effectively lied to during the sale. If your wife simply made a mistake and did not guarantee the dog's breed in any written statement, a claim against her is probably not actionable.
Answered on Aug 19th, 2013 at 2:38 PM