Zoonotic diseases are diseases that are passed from animals to people. Over fifty known zoonotic diseases (also called “zoonoses”) are recognized today. Amazingly, approximately 75% of all human pathogens (germs) originally came from animals. Approximately thirty of the known zoonoses are carried by cats and dogs. Some households have non-traditional (or exotic) pets, like reptiles, birds, amphibians, fish and small mammals. These non-traditional pets pose different health risks that should also be addressed by their owners.
Traditionally, zoonoses have been classified into categories based on how the infections are acquired. Aerosol exposure (e.g., contact with respiratory secretions after a cough or sneeze) occurs with diseases such as Bordetella, which causes Kennel Cough in dogs, but rarely affects people. Chlamydia, a respiratory tract disease in cats and people, is another example of a zoonotic disease spread through aerosol exposure.
Digestive tract exposure occurs when the organism enters through the mouth. This most often occurs when microscopic eggs or cysts are inadvertently ingested during gardening, playing outside where animals eliminate, or after petting or contact with animals that may have eggs on their fur or in their saliva. Some examples of these infections include Giardia, Toxoplasmosis, Roundworms, Campylobacter, E. coli, and Salmonella.
Many zoonotic diseases are acquired through bites, scratches, other types of skin penetration, or contact with infected discharge (e.g., pus). Some organisms infect the superficial layers of the skin, such as Sarcoptic Mange (Scabies) and Dermatophytosis (Ringworm). Other organisms, like hookworms, penetrate intact skin and migrate under the skin, causing red, raised inflammatory tracts. Still other organisms get into the body through natural breaks in the skin, animal scratches or bite wounds. This group of diseases includes Rabies, Bartonella (the organism that causes Cat Scratch Disease), Capnocytophaga (a common bacteria in dogs’ and cats’ mouths that can cause a very serious disease in immune-suppressed people), and Methicillin Resistant Staphylococcus aureus (MRSA).
Some zoonoses cause more serious illness in immune-suppressed people, such as people with HIV infections or those on chemotherapy or who have had bone marrow or stem cell transplants or splenectomies. This group of people has a much harder time fighting off infections.
Good hygiene and simple preventive measures are the simplest ways of lessening the risk of contracting zoonotic diseases from pets. Standard precautions include:
- Proper hand washing or sanitizing – after handling animals, animal products (e.g. bedding, food and water bowls, litter boxes), gardening, and before eating.
- Disinfecting bite wounds and scratches – good, old-fashioned scrubbing with soap is best. See your doctor when necessary.
- Wearing gloves – especially with litter box cleaning and gardening.
- Providing appropriate veterinary care for pets – vaccinations, deworming, heartworm prevention, parasite prevention (e.g. fleas and ticks), and prompt medical attention when pets are ill.