I have a female black lab rotty cross, about 6 months old randomly throwing up, but she's not throwing up anything. It has happened 3 times now in the past week or so.

When you say she's not throwing up anything do you mean that nothing comes up, she's just gagging, or she's just bringing up phlegm, or water, no food?

It's a kind of phlegm, white, kind of looks like spit.

It's a kind of phlegm, white, kinda looks like spit.

Have you started him on new food? Has he recently gotten his shots? Has this happened before or just this past week?

Also, what is he doing right before this happens? Drinking, running, just came back from a walk, or does it just happen any time of the day, no matter what he was doing beforehand?

Its OK she's stopped she's okay now thanks