my dog has dandrif and i want to know how i can help her get rid of her dry skin

hi my dog who has seen a vet not long ago but i dont remember when has dandrif, and typicly someone whould say just give her a shower. but i learned that shampooing a dog ruins there skin and makes it dry and since i already shampood her this year and dont want her to have even more big pieces of dandrif i tried to come her, i tried all different sizes and even tried persanily with my hands to take some pieces out, but the more i much her hair and tuch her skin the more dandrif comes out and unlike humans its bigger pieces and i was curious if there was some kind of lotion or medicien that can help. im brining my birds this saturday i believe maybe its the 16th to the vet, and could try to buy something, also my dog has artherites and the medicien only makes it worse, so we stoped it and so did other close friends with older dogs because the same affect acored for them, do you have any sudjestiants i can ask my doctor for.
thanks sincerely sapsapy
thank you so much for your help
hmm im not sure if you might spell it dandruff

[Aleda M Cheng, D.V.M., C.V.A]

Give her 1000 mg of Omega 3 fatty acids by mouth twice per day.   Omega 3 fatty acids are available from fish sources, i.e.: Marine Lipids or Marine Algae sources and can be purchased over the counter at drug or health food stores.  A good brand is Carlson Fish Oils.  Please begin with a lower dose and gradually increase to the recommended dose over a 2 week period of time to avoid stomach issues.