What Diseases do Squirrels Carry? Squirrels carry many diseases communicable to humans. Though different species are capable of transmitting different diseases, some of the common illnesses passed on by squirrels include plague, Colorado tick fever, encephalitis, tularemia, and louse-borne typhus. Additionally, squirrels may act as hosts for ticks and other pests, which contributes to the spread of Lyme disease. Since many of these diseases are fatal when left untreated, individuals should monitor for symptoms and seek medical attention after coming in contact with squirrel urine and feces as breathing in particles of the animal's excrement is the most common method of disease transmission. Preventing Disease The best way to prevent the spread of disease is to avoid contact with squirrels and their waste, and wearing gloves and masks helps reduce the possibility of contracting illnesses. If infected squirrels appear in residential areas, contacting professional wildlife removal services is recommended. As diseases can be transferred via urine, feces, scratches, and bites, untrained individuals should never approach or handle squirrels. Professional technicians remove problematic animals and sanitize homes to ensure the safety of all nearby individuals.