Calling oneself a nonprofit does not mean legitimacy or that the rescue is even registered with state or federal agencies. Donations are only tax-deductible if one is federally approved 501c3 organization.
Avoid rescue groups that advertise nothing but purebred or “designer” puppies. The puppies are purchased from mills but described as "breeder surrenders." It's the newest scam in rescue!
Legitimate, reputable rescues ALWAYS spay and neuter animals before adopting them out, helping to reduce pet overpopulation! There is simply NO excuse for adopting out unaltered animals!