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.
Legal entities have the right to own property, the right to trade, the responsibility to repay debt, and the responsibility to account for themselves to regulators, taxation authorities, and owners according to rules specified in the relevant legislation.
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.