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.
Although self-insured plans are frequently administered by an insurance company, it is the employer and not the insurance company that bears the risk for paying claims. Federal law exempts self-insured employer plans from state insurance regulation. The same is true of health & welfare benefit plans (union plans).