Nevermind, I did some internet searching and found it. It's PCBs (toxic chemicals added to the oil) that cause the cancer, not fish oil itself.
I have not heard of fish oil or vitamin E helping liver problems, but they are great things to add to your dog's diet if his liver can handle them. I hope he feels better soon!
Hi Rachael it's in one of the links that I hyperlink above, specifically an MSU study published last year, PCB is a separate issue entirely. Fish oil can increase your vitamin A to a toxic level (causing fatty liver), raise your ALT, it is an anticoagulant (bleeding), truth is no one really knows the long term health benefit when it comes to feeding it to dogs, everyone assumes it's good for human therefore it'll be good for dogs too. Again, the FDA does NOT regulate supplements, NO ONE can vouch for the purity / quality of the fish oil, that's why we have a problem.
Supplement is ONLY needed when you are lacking and cannot obtain enough from a balance diet, too much of a good thing can be deadly. OTC + Supplement is not safer than Rx, always check with a trusted medical professional.
There are better safer ways to obtain Omega 3, 1 tsp of fresh grind flax seed is good enough, no need to go with a refrigerated flax oil (easily go rancid + overdose can cause prostate cancer)
A work friend has a Yorkie with a liver shunt. Not sure if that's a similar condition, but he is doing well and my understanding is the prognosis is good.
Hope all goes well. If they suggest a prescription diet, please disregard all the postings on the internet about what foods are "good" or "awful." The prescription foods are made for a reason, with science to back them up. :)