I was diagnosed with periodontal disease, should i get a 2nd diagnosis?

Certainly, however : Periodontal disease is very straightforward to diagnose. If there is bone loss resulting in deep spaces between your gums and your teeth, them you have periodontal disease. You are best off addressing it sooner rather than later since periodontal bone loss is not reversible, it can only be controlled.

Second opinion ?: Sure you can get a second opinion if you think you need it, the dentist who dignosed you with the periodontitis must have showed you on the x rays if you have vertical bone loss alonge with generalized inflammation of the gums, pockets, teeth shifting .Etc. But a second opinion does not hurt..