It’s a question I've been asked many times as a veterinarian: Can my cat eat dog food?
If your cats are anything like mine, they are perpetually hungry. They show up at the first sign of food, be it human, feline or canine. But snacking from your or your other pets’ bowls should be a firm no-no.
It’s not a good idea to feed cats too much of any food. Cats who nibble from the dog’s bowl are ingesting more calories than they should, and with feline obesity at an all-time high, any extra calories mean bad news for the health of our cats.
But more importantly, cats shouldn’t be fed dog food because they are obligate carnivores. This means that they must eat meat to survive. The reason is because of an amino acid called taurine. Cats can’t produce enough taurine naturally, so they must rely on their diets to provide it. Taurine can only be found in animal products like meat and eggs.
Dogs, on the other hand, are not obligate carnivores. I’m sure you’ve noticed your dog chowing down on grass in your backyard. This is because dogs are omnivores – they consume both plants and animals. Dogs don’t need to consume taurine because they are able to synthesize it on their own. Therefore, their foods are not generally supplemented with this amino acid.
If your cat only east dog food, and doesn’t get enough taurine in her system, she can develop a heart condition called dilated cardiomyopathy, in which the muscles of the heart weaken and the heart enlarges. When this occurs, the heart is unable to pump blood effectively, and fluid builds up in the lungs, leading to congestive heart failure.
In 1980, it was discovered that a major cause for dilated cardiomyopathy in cats was a diet deficient of taurine. When this discovery was made, all commercial diets began being supplemented with taurine. For this reason, dilated cardiomyopathy is thankfully much less common in cats than it used to be.
Because taurine deficiency is a common resulting condition in cats who consume only dog food, I always recommend against this practice.