Chihuahuas can indeed be service dogs, providing critical support to individuals with disabilities. They are alert, agile, and caring, making them suitable for tasks such as helping the deaf and seeking help for epilepsy. However, they must be handpicked as some can be too aggressive. Chihuahuas are best suited as emotional support dogs, as they have social skills and can provide comfort to people suffering from depression or anxiety. With proper training, they can also be trained to be guard dogs and detect seizures or changes in blood sugar levels.