Tuna Intended for Human Comsumption

• Many people try to feed their animals human food, thinking they are treating their cats like a part of the family. Most people have given their cats canned tuna that is intended for human consumption. However, this is a bad idea, as this type of tuna is not good for a cat to eat.
  
  

Mercury

• Fish generally has mercury in it. The amount depends on the conditions of the water and location of the fish. Mercury builds up over time, and giving your cat tuna on a regular basis can lead to mercury toxicity.
  
  

Lack of Proper Nutrition

• Canned tuna intended for humans lacks the proper nutrition that your cat needs, such as vitamin E. In fact, most canned fish lacks nutrients needed for a feline. Canned tuna also lacks important nutrients such as copper, iron and calcium.
  
  

Steatitis

• Steatitis is a painful feline intestinal disease. It is also referred to as Yellow Fat disease. One cause of steatitis is consumption of fish high in unsaturated fatty acids, such as tuna.
  
  

Bad Cat Breath

• The least important negative side effect of feeding your cat tuna is the bad breath your cat will end up with. The bottom line is, no one wants to pet a cat with bad breath, so leave the tuna out of your cat's diet.