Did your Beagle eat a tomato? Not sure if the tomato is safe or not? In general, ripened tomatoes are safe for your Beagle if given in small quantities.
However, you must be careful that your Beagle does not have access to unripened tomatoes. If your Beagle eats a tomato from a vine, make sure he does not eat the leafy greens as these parts contains most of the toxins. Tomatoes and potatoes are members of the Solanum species and are part of the nightshade family of plants, which contains toxic alkaloids that can be harmful to pets.
If these toxins are eaten in large quantities your Beagle may start to show signs of excessive drooling, vomiting, diarrhea, drowsiness, confusion, weakness, behavior changes, dilated pupils, or even a slowed heart rate. If your Beagle has any of these symptoms, call your veterinary clinic immediately.
Source: My Beagle Ate a Tomato!