Animals can bring tremendous joy to our lives, but they can also make us sick. Every year, tens of thousands of people fall ill to diseases transmitted through animal contact. These conditions are known as zoonotic diseases, or zoonoses. Here are some of the most common.
Salmonellosis
This very common bacterial infection can be transmitted through direct contact with animals such as dogs, rodents, and reptiles as well as through consumption of infected food. Symptoms include diarrhea, fever, headache, and spleen enlargement.
Leptospirosis
Contact with the urine of infected dogs, mice, or rats, or with urine-contaminated materials, can quickly spread this debilitating disease. Symptoms, which present in two phases, include headache, muscle ache, stiff neck, eye pain when viewing bright light, and inflammation of nerves of the eyes, brain, and spinal column.
Tuberculosis
The zoonotic form of this bacterial disease is commonly acquired from cattle by inhaling droplets in the air or ingesting contaminated dairy or meat products. Symptoms include fever, fatigue, and, in severe cases, chronic pulmonary disease, which can be fatal.
Melioidosis
This bacterial disease is commonly transmitted to humans through soil or water contaminated by sheep, goats, or pigs. It can also be directly transmitted by these and other animals. Symptoms include fever, chills, skin lesions, and swollen lymph glands.
Pox diseases
A variety of animals, including primates, pigs, horses, and birds, can spread poxviruses, which are acquired through contact with infected animals. Some poxviruses can be acquired by inhaling airborne particles and some by skin contact. Symptoms include localized lesions, rash, fever, sore throat, malaise, and encephalitis.
Rabies
Dogs are the best-known culprit (see Old Yeller), but almost all mammals can spread the rabies virus, which is commonly transmitted via bites or other contact with infected saliva. Symptoms include headache, fever, salivation, excessive perspiration, inability to swallow, and seizures.
Viral hemorrhagic fevers
These illnesses include some of the world’s most terrifying diseases, including Ebola, Lassa fever, and Marburg hemorrhagic fever. The viruses that cause these diseases are transmitted by a variety of animals, ranging from rodents to monkeys, depending on the specific virus. Symptoms include high fever, sore throat, diarrhea, vomiting, and hemorrhage. Several of these diseases have high mortality rates.
Giardiasis
This parasitic condition is the most common waterborne diarrheal disease in humans. It can be spread by a wide variety of animals, both wild and domestic. Paths of transmission include consuming contaminated water or food, person-to-person contact, and contact with infected animals. Symptoms include nausea, severe diarrhea, and fatigue.