Sometimes dogs limp or appear to be limping on the paws opposite to the one that actually hurts. If you still can't find anything, you should probably consult your vet. I doubt it's related to getting fixed, but crazier things have happened.
Your legal entities are required to pay payroll tax and social insurance such as social security on your payroll. In Oracle Fusion Applications, you can register payroll statutory units to pay and report on payroll tax and social insurance on behalf of many of your legal entities.
Legally, employers are allowed to say just about whatever they want to your prospective employer. Currently, there is no law that states that employers are only allowed to confirm your employment and what your start and end dates were. If you were fired, they can disclose that information.