You should make sure your blue tongue skink gets a balance of fruit, vegies, greens and meat everyday.
my blue tongue is on a strict healthy diet. at the moment, every day she will get a mix of raspberries and mango (fruit), golden squash (vegies), endive (greens), small amount of cat food and two superworms (meat).(every third day i mix in red cabbage)
If you are going to feed them cat/dog food, it's best to give them cat food, its better for them and smells better too! check the labels and only buy 100% meat brands, and NO FISH. I buy single packets of whiskas chicken and vegetable, and keep it in the fridge. I always chop all the greens, vegies and fruits into small diced pieces, or finely choped, and mix it into her meat, that way she eats them too without much fuss and gets her vitamins and such
i have a basic list of things they should get daily, and things they can have on occasion, made from the caresheet at bluetongueskinks.com:
A - Always
O- Occasionally
R- Rarely
GREENS
A - Collard greens, Mustard greens, Endive and Escarole.
O- Bok Choy, Kale, Red/Green Cabbage
VEGETABLES
A- Squash (spaghetti squash is the best for them)
O- Cucmber, Celery, Pumpkin, Asparagus
R- Zucchini, Olives
FRUITS
A- Fig, Mango, Papaya, Raspberries
O- Apple, Honeydew, Grapes, Pineapple
MEATS
A- Silkworms
O- All other worms (Butter/Earth/Super/Wax)
R- Pinky Mice, Hard Boiled Egg, Chicken
Pinky mice and hard boiled eggs are high in fat so theyre not very good to give them on a regular basis. Worms are the best source of protein.
Note: I made this list for convenience purposes, I chose the things I would most likely buy for myself, and can find easily (so no, not all the foods are on there). I mean, red cabbage is very large! and I only have one adult bluey so she's not going to eat it all in a hurry!
Hope this helps