A common misconception is that you should not feed table scraps to your pet. In reality, table scraps can be a great way to get a bit of variety into your pet's diet!
The important things to remember are MODERATION and SELECTION!
When you add table scraps to your pet's diet, just remember that you are feeding extra food, therefore extra calories, just like feeding packaged treats. While for larger pets of healthy weight this may not be an issue, but for small dogs, cats or overweight pets be sure to cut back on other treats/food.
Like anything, moderation is important - no more than 10% table scraps is a good rule of thumb. You don't want to give your pet so many scraps they will not eat their regular food! In addition, avoid "rewards" for begging at the table. Ways to avoid begging include feeding scraps away from your meal time or place an item in their bowl before hand.
Meat pieces, veggies and fruits are suitable and healthy for most dogs (see a couple exceptions below). Most cats will be more into the meat only scraps!
Sugary foods are not recommended and foods consisting largely of fat should also be avoided, as some pets may be susceptible to pancreatitis (eg: fat chunks off a roast, bacon, pepperoni pizza). Plus, if your pet has a sensitive stomach, be sure to exercise caution with table scraps, both in the amount and the selection, such as choosing just one food instead of numerous at once.
Do NOT feed:
Chocolate - Or anything with chocolate, as it is toxic to cats and dogs
Grapes and Raisins - Can cause liver and kidney failure
Onions and Chives - They are poisonous for dogs and cats causing red blood cell damage
Alcohol - Besides disorientation, alcohol can lead to coma or death in larger amounts
Avocado - May cause digestive upset and heart problems
Dough with Yeast - Yeast may expand in the stomach, causing discomfort, gas and in higher amounts may rupture intestines
Macadamia Nuts - Toxic to dogs and cats
Xylitol - Normally found in sugar-free products, is very toxic and can cause liver failure, seizures and low blood sugar
Cooked bones - They may splinter and cause mouth or digestive damage