E.M.
You can also use the Cran Grape and Cran Apple juices. They're sweeter and he'll most likely drink them easier for you. As for length of time--it depends on the severety of it. I've had symptoms last up to 2 weeks after initial treatment. If you're giving him orange juice--please note that o.j. hits me harder than coffee. I have to run something awful several times in an hr after I've had o.j. to drink. This could be his problem as well.