What happens if a dog eats cat food long term?

A dog eating cat food long term may cause health problems, because cat and dog food are designed for different needs. Cat food usually has higher protein and fat; long-term feeding may cause excess nutrition and raise obesity risk.

Second, taurine in cat food is vital for cats’ eyes and heart but not needed by dogs, so long-term cat food may overburden the dog’s liver. Finally, dogs are omnivores needing starch, vitamins, and fiber; cat food is low in these, so long-term feeding may cause vitamin and trace-element deficiency.