Rabbits and deer frequently feed on vegetable plants. Pets, squirrels and bugs tend to do the same. Home remedies for eaten tomato plants include prevention through fencing or kitchen products, or confronting the critters to get them off the tomato plant.
Fencing around the garden is the most effective way to deal with animals that might eat tomato plants. For a more cost-effective approach, stake chicken wire or other narrow-grid wire fencing to surround the tomato plants to keep rabbits and other small animals away.
Place shiny objects on the ground around the tomato plant, like aluminum foil, to keep animals away--especially dogs. Push U-shaped fabric pins into continuous strips of aluminum foil to hold it in place on the soil, or toss handfuls of soil or stones onto the foil periodically down its length. Scattering moth balls around plants may help, but this is not a suitable deterrent if small children can access them. Using mothballs requires careful watering to avoid getting the moth balls damp; replace the moth balls after rainfall. Mix 2 tbsp. hot sauce sauce or ground red pepper and 1 tbsp. white glue in 1 qt. of water. Use a brush or your fingers to paint the mixture on the main stem of the tomato plant and some outer leaves.
Slugs are attracted to the smell of stale beer. Slightly imbed a saucer of beer in the ground to collect slugs. Apply 2 to 3 inches of mulch, like organic leaf mold, around the base of the tomato plant. The moisture-retention nature of mulch helps to promote healthier plants and provides a home for good bugs, like predatory ground beetles.
Plant basil or marigolds in a solid line about 12 inches away from, and completely surrounding, vegetable plants to deter rabbits, beetles and hornworms.
Pick slugs,caterpillars or worms, like the green hornworm, off by hand. If you're squeamish, hold a can or jar beneath the worm and use a garden hand tool or stick to push it into the container. You can also remove some bugs with a blast of cold water from the garden hose.