Do I have a claim if I had an injury that was treated and then treated by a 2nd doctor because the first treatment didn't work?

It would depend on whether the first doctor's conduct fell below the medical standard of care.  And if so, you would also need another doctor (an expert witness) to testify to such in a court of law.  Some states even require that an expert be consulted and willing to testify before you can file the actual lawsuit.  Finding an expert witness can be difficult and expensive.  Thus, if you are considering filing a medical malpractice lawsuit, I would recommend finding the assistance of an attorney.  It is also important to note that you are likely limited to a statute of limitations.  Most states are 2  years but many are different and an attorney would need to look at the facts and details of your potential case to best inform you of such.  If you are desiring to proceed with legal action, I recommend obtaining your medical records from both doctors related to this and consulting a local attorney.  Best of luck! NOTE:  This response is general in nature and should not be considered legal advice.  No attorney-client relationship exists or is formed by this response.