You really should try and feed the cats with cat food only. Dog food lacks some nutrients that cats must have (and dogs don't).
Taurine for example is an amino acid that is very important for cats and isn't found in dog food. Without it, the cats may suffer from heart disease and problems with their night vision.
Maybe you can set different feeding hours for the cats and dogs and seperate them at feeding times? I think you should discuss this with your vet. Maybe he or she would like to run some special tests on the cats to check for nutritional deficiencies.
Also, if your cats hunt, I guess they need deworming at least once or twice a year. Eating small rodents and birds they're more exposed to different parasites.
I can imagine it must be quite a task taking care of so many cats