Feeding my cat a healthy diet ?

No! Any milk (besides milk from a cat) is bad for them! It's hard to digest, and can make them really sick. The foods we eat are processed and have additives that are not good for us...let alone our animals. Fish is also not great for them, and can cause loose, oily stool, as well as bad gas. I would stray away from any human food. They make treats that are fine for them that are made of chicken or fish flavored, etc. The best treats I've found that are natural (100% real meat) and that my cats love are called PureBites and they come in a bunch of varieties (turkey, chicken, shrimp, etc).

No it isn't okay. Some human foods will make cats sick. I'll paste in a site that will tell you what isn't okay. Under normal conditions, cats would not eat fish. You don't see lions standing in the river catching fish to eat like a bear would.

No to cow's milk. The majority of cats are lactose intolerant and you can make your cat have diarrhea by feeding it milk. Evaporated milk (in the can) is much less harmful; also goat's milk in the dairy section (also heard it's in a box in either the baby section or pet section at Walmart and doesn't need refrigeration until opened) are both okay to use. Catsip is a product you can buy at a pet supply store that would probably work. Normally, a cat never needs milk after it is weaned.

Cooking for dogs is tricky. Yes, they need supplements. That is why I only ever cooked for mine as an addition to his good quality kibble. You can seriously hurt a dog by not giving them the nutrients that need. I did get some recipes form our vet. Maybe yours can provide recipes. Also, go to the library and check out some books on dog nutrition and home made food. I remember you are supposed to add bone meal but I haven't any idea how much for what weight of dog. Again, research well before harming your dog. There was other stuff to add also but I honesty have forgotten what. We always felt best with a good quality kibble and a few cans... Look at the ingredients lists. Meat (not meal) of some type should be the first ingredient. There should be no corn, wheat or by-products. Innova, Wellness, Orijen & Merrick are a few of the good brands out there.