if you go back to google & type in "Ucerax for dogs" you'll see lots of info about giving these to dogs.
Is Oscar a westie? We have a westie/yorkie cross, Basil, who has suffered a lot with his skin but it is very seasonal & during the winter months he isn't as bad. We found that by switching his food to Burns it helped calm his skin a lot. If you haven't already visited their site then have alook. They are very helpful if you ring them.
http://www.burns-pet-nutrition.co.uk/.
Good luck!