Uh oh. Feeding fish to our cats and dogs is problematic. Although the omegas in fish are important to the health of our cats and dogs, feeding fish, especially fish in canned and dry foods, can cause serious health issues.
#1 Mercury
Many canned and dried foods have fish in them with frighteningly high mercury levels. Fish at the top of the food chain; tuna, salmon, trout and swordfish have mercury levels above what's considered safe. In addition, many fish have high concentrations of PCB's and DDT, especially when sourced outside of US waters where DDT is banned.
#2 Ethoxyquin
This toxic chemical, banned in human foods, is used to preserve fish and other ingredients. It used to be added to many pet foods until consumers demanded it's removal. However, if the fish was preserved with ethoxyquin before being added to the pet food, the pet food manufacturer is NOT required to list it on the ingredient label.
#3 Farmed Fish
Almost all fish in pet foods is farmed. According to Dr. Karen Becker, farmed fish meal is a source of mycotoxins.
#4 Magnesium Overload
The magnesium in fish has been linked to urinary and kidney issues in cats. Any cat who has had or is vulnerable to kidney issues (many cats) and urinary issues needs a fish-free diet.
Safe Fish?
The good news is that there are a few good options to provide you beloveds with the important omegas from marine sources without exposing them to the above problems. Sardines packed in water and wild caught salmon rotated with poultry, beef and bison are okay in limited amounts. My concern for these is over fishing. However, fed infrequently in small amounts can be a responsible choice.
Something Better?
The safest, purest marine lipid supplement I have found is "Moxxor" green lipped mussel sustainably grown in New Zealand. Dr. Jean Hofve and Celeste Yarnall introduced me to it a few years ago and it's the one I recommend to all my clients. Drs. Hofve and Yarnall believed so strongly in the product and company, they've served on the Board. We take it too!
Here's a link: http://katesolisti.moxxor.com/product (By way of a disclosure, I’m a distributor, so I do get a commission if you order some. I can also give you a discount code, so email me if you're interested in ordering and saving. Thank you.)
I don't recommend krill oil since it is the only food source for many marine mammals including whale species. Harvesting it means invading their ocean feeding, breeding and calving grounds.
If you're thinking of substituting flax or another plant oil, know that dogs and cats can't get enough EPA and DHA from plant oils.
I hope this has helped you understand the challenges of feeding fish and fish-based supplements to your beloveds and given you some clear direction. If you need any help creating a wholesome, balanced, affordable diet for them, including the appropriate amounts of healthy omegas, please contact me here.
With Love, Your Voice of Animals,
Kate
PS For more detailed info, please see D. Karen Becker's excellent article here