ah ok well flaxseed oil and cottage cheese in *normal* doses are generally safe for dogs unless of course they have allergies to either. It sure sounds to me like maybe this is a digestive allergy/intolerance or maybe just too much of a good thing?
same with humans...I take flaxseed oil capsules daily and I eat cottage cheese a few times a week.
I do hope Nina is ok and you too. Good that you are taking her in to be checked out.
hope you are feeling better too