If might seem an odd question at first, but if you hear someone asking if rabbits can eat dry cat food be sure to tell them no. It’s not usually the case that someone intends to feed them the cat food, it’s usually that they have a house bunny and know it will come across the cats bowl and probably have a nibble.
My advice is to move the cat bowl out of reach. Rabbits will probably eat some and it can cause them some serious digestive issues. Cats are very different animals and have very different nutritional needs.
Their food is high in protein and typically contains meat. Rabbits are herbivores, they only like plant matter, not meat.
Rabbits diets require a lot of fiber to keep their digestive system healthy. They get this from Timothy hay and pellets. You should also be giving them some fresh vegetables and leafy greens each day, so as you can see dry cat food it the opposite of what they should be eating.
Let this serve as a warning that you should keep all foods out of their reach in the home. You should rabbit-proof your home just as you would child-proof it. Giving them the odd treat like fruit is fine, but keep this to a minimum as fruits are high in sugar which can cause stomach upsets.