You have heard that cats love tuna, but did you know that tuna can be harmful to your cat?
Tuna contains small trace amounts of mercury as all fish do. Cooking the tuna does not lower the mercury levels. 
Vitamin E is very important to your cats diet and tuna along with several other fish have very little vitamin E in them.
- Several foods that you and sometimes your dog eat can be hazardous to your cat. It can cause digestive upset or severe illness. Canned tuna can cause your cat to become malnourished because it lacks the proper levels of vitamins and minerals your cat needs. Tuna also has a lot of unsaturated fats which excessive amounts in your cat´s diet can be harmful.
- Cats can develop yellow-fat disease from having too much tuna. When your cat eats mostly tuna that is not specifically formulated as cat food, your cat can become deficient in Vitamin E. The dietary unsaturated fats from the fish are oxidized by a bio chemical called peroxidase into a substance called ceroid. Ceroid, a abnormal pigmented yellow-brown breakdown product of unsaturated fat oxidation, is formed and deposited in fat cells. The result is yellow-fat disease.
- The Ceroid triggers an inflammatory response by the immune system acting as it where a foreign invader. The subcutaneous fat of cats affected with yellow-fat disease causes pain; these cats will become hypersensitive and will avoid being handled and petted. Their muscles will become weak and atrophy. They don´t want to move. As this disease progresses the body fat degenerates and is replaced by fibriotic tissue leaving the skin hard and bumpy. Cats that are affected may also develop fevers that are not related to any infection.
- Treatment will include the discontinuation of the
inappropriate diet, giving therapeutic doses of vitamin E; cortisteroids could also be prescribed to help with the inflammatory process.
There are other problems that make feeding your cat tuna a bad idea. Some researchers say tuna contains specific substances (allergens) that stimulate allergic like disorders in cats.
To keep your cat healthy, you should avoid feeding tuna or any other food made for human consumption. Your cat should be fed a nutritious, well balanced cat food specifically formulated for them. This is the best way to avoid unwanted health problems and you can be sure your cat is receiving the right vitamins and nutrients he needs to live a quality life.
