We wanted to get our dogs on Salmon oil. I ordered a big bottle of it with the squirt pump. It was messy and I wasn't getting accurate measurements. I found some salmon oil tablets at Costco that work great. We supplement morning and evening and it's neat, measured and the dogs love them.
One word about salmon oils and fish oils in general: Penny & Maggie's Mom and I attended a nutracutical seminar put on by one of the vets in the veterinary clinic where I take my pups. The vet who gave the lecture was very critical of fish oils, glucosamine supplments and Sam-E formulations from Sams and Walmarts in general because the labeling doesn't include information on the sources of the ingredients. For fish oils she was particularly concerned with mercury levels. She cautioned if they don't include the source of the fish, assume the worst. The salmon oil capsules from Costco "claim" they are from pure sources and waters, but since they aren't regulated by the FDA no one can know for sure. The vet also cautioned to get formulas that concentrate on the Omega 3s, not Omega 6s because too much Omega 6 can be detrimental (I don't remember what the detriment is, sorry). She gave us some great handouts and one of the warnings for fish oils was in some dogs overdosing can cause lethargy or increased itching. Also, if you dog is going into surgery, best to hold off on them for a bit because they do tend to cause increased bleeding. I know that is true for humans too.
I hope this helps! I love the coats on my dogs with the new salmon oil, but unfortunately it has been so wet and rainy here they are itching up a storm and having more allergies, yeasty ears and issues. Toby even got a hot spot, in December!