Owners: How much medical info do you disclose to Sitters?

Scenario: I've returned with a dog on our walk, and I notice a bulge that's coming from their mouth (which left me to be concerned). When I inform the owner of said bulge, they mention that it's a "benign tumor," something that wasn't brought to my attention when I asked about any health conditions.

To Owners: Would you have disclosed this to your Sitter prior to the start of their sit?