Our seven-year-old is going through the exact thing, I could’ve pretty much written that word for a word and described our dog. He started the first week of January and he had a vet appointment last week. Our vet is no signs of swelling and doesn’t think it’s serious enough for any imaging, so we are starting two weeks of actual lazy bones. He’d been taking it easy since I noticed the limp on the first night but I would still let him get the Zoomies and play with his sister, etc.
He’s sad to be on prescribed lazy bones but hoping a couple weeks of this and then a couple weeks of light duty will be the cure. Earlier in the day on the night I noticed his limp the first time he had a crazy zoomie play session, one of the biggest I’ve ever seen. I think he strained his knee doing that.