Is this zucchini damage due to vine borer
The good news is that this is not squash vine borer damage. That causes complete plant wilt and collapse like a wet cloth.
Your first and third photos do not show anything terribly concerning, but your second shows a stressed plant.
This may be a combination of factors of tough weather lately (older plants can sprawl open like that) and perhaps squash bugs, which are common, but may evade detection for a while as the young feed under the leaves and adults are secretive and fast moving/elusive.
Take a look at this crop page for summer squash: http://extension.umd.edu/growit/vegetable-profiles-summer-squash
and this one for squash bugs: http://extension.umd.edu/growit/insects/squash-bug You should monitor for them and other pests regularly. You can try putting a board down near the plant overnight, and checking under it in the morning and squishing those found.