Need some help- Retailiation

[llij]

What is the name of your state (only U.S. law)? Ohio
My animal was injured during a common simple procedure (by the vet), as a result, the animal is losing an eye. The vet has been very reluctant to help correct the problem and has been very rude so I had to go elsewere to try to get it fixed. I sent a letter asking him to take responsability or I would have no choice but to take him to small claims court to recover my losses as well as turn him into the lisencing board. He called me and said if I turn him into lisencing that he would turn my letter over because he had someone "lay eyes" on my threats, I hate that I had no witness's for that. I know my letter is well within my civil rights, there were no threats, I did have an atty look it over and would be more than happy the part in question here. My question is, this man needs to be turned in, not only is he threatening his client, he is careless with the animals. But i know he has more money than I do, and do not want to have to pay an atty to defend me over stupid charges. I am pretty sure he is bluffing, but does have me worried about what kind of retailation he is capable of.