Many people don’t know it, but humans and animals can share a wide variety of diseases. Some are transmitted from animals to people, and others can travel in both directions. This phenomenon is known as zoonosis and can affect pets as well as wild or farm animals.
Below, we review some common human diseases that can also affect animals:
1. Influenza (Influenza)
Humans can spread the flu to dogs, cats, ferrets and other mammals. There are also specific strains that affect birds and pigs.
🔹 Example: Avian or swine flu can infect humans and animals by crossing the species barrier.
2. Tuberculosis.
Caused by the bacterium Mycobacterium tuberculosis, it can be transmitted between humans and animals (especially cattle and primates).
🔹 Humans can spread it to pets or zoo animals in close contact.
3. Salmonellosis.
Although often associated with poultry or reptiles, humans can also transmit salmonella to their pets when handling contaminated food.
4. COVID-19.
SARS-CoV-2, the virus that causes COVID-19, has been detected in cats, dogs, mink and big cats.
🔹 Transmission is usually human-to-animal, although the opposite has been seen in some cases (such as in farmed mink).
5. Ringworm (Dermatophytosis)
It is a fungal infection that can be easily transmitted between humans, dogs, cats and other animals.
🔹 It is spread by direct contact with infected skin or contaminated surfaces.
6. Intestinal Parasites (Giardiasis)
Both humans and animals can suffer from giardiasis, caused by the parasite Giardia intestinalis.
🔹 It is transmitted by contaminated food or water, and by contact with infected feces.
7. Rabies.
A fatal viral disease affecting the central nervous system. Although more common in animals, it can be transmitted to humans by bites.
🔹 Dogs, cats, bats and foxes are common vectors.
8. Hepatitis E.
Some studies have detected Hepatitis E in pigs and other animals, suggesting possible cross-contagion with humans.
9. Intestinal worms (Toxocara)
Dogs and cats can carry these parasites that also affect humans, especially children.
10. Campylobacteriosis.
An intestinal bacterial infection that affects both humans and pets, especially puppies and kittens.
🧬 Human diseases that animals cannot catch.
- HIV/AIDS (Human Immunodeficiency Virus).
🔹 It only infects humans. Although there are similar viruses in apes (SIV), HIV is not transmitted and does not affect other species. - Measles.
🔹 It is highly contagious among humans, but does not affect pets or most animals. Only certain primates can be affected in laboratories. - Varicella and herpes zoster (Varicella-zoster virus).
🔹 Exclusive to humans. Animals cannot catch these viral diseases typical of childhood or adulthood. - Infectious mononucleosis (Epstein-Barr virus)
🔹 This virus, common among humans, cannot infect domestic animals. - Mumps.
🔹 It exclusively affects humans, there is no evidence of contagion to other species. - Rubella (German measles)
🔹 Specific to humans. Not documented in animals. - Hepatitis B and C.
🔹 Although hepatitis exists in animals, the human B and C variants only affect humans. - Celiac disease (gluten intolerance).
🔹 It is a human autoimmune reaction to gluten. Although some animals may have digestive sensitivities, they do not suffer from celiac disease as such. - Human autoimmune diseases (lupus, multiple sclerosis, rheumatoid arthritis…).
🔹 Although autoimmune diseases exist in animals, human forms are neither transmitted nor affect them. - Syphilis and gonorrhea (human bacterial STDs).
🔹 These sexually transmitted infections are specific to humans. Although animals have their own STDs, they cannot contract these human variants.
How to prevent contagion?
- 🧼 Wash your hands after touching animals or cleaning their excrement.
- 🩺 Take your pets to the veterinarian regularly.
- 🧴 Disinfects surfaces and utensils used by animals.
- 🐾 Avoid close contact if you are sick.
- 🦠 Vaccinate your pets as directed by your veterinarian.
Conclusion.
Many diseases make no distinction between humans and animals. Living with pets and farm animals entails a health responsibility, not only for their health, but also for our own. Prevention, hygiene and veterinary check-ups are key to avoid cross-contagions and protect the whole family.
