Man's best friend can sometimes carry health risks. Dogs can transmit certain diseases to humans—a phenomenon known as zoonosis. These infections, caused by bacteria or viruses, can pass from animals to people (or vice versa). As veterinary experts note, while the risk remains low in developed countries, awareness is key, especially for vulnerable groups like children and the elderly with weaker immune systems.
Zoonoses spread through direct contact (bites, petting), ingestion of contaminated food, inhalation, or insect vectors. Though rare, understanding these threats helps protect families and pets. Here are three common examples backed by health authorities like France's Institut Pasteur.
Leptospirosis, on the rise in France, is caused by Leptospira bacteria found in urine-contaminated damp areas frequented by rats, nutria, hedgehogs, wild boars, or livestock. Dogs pick it up via skin, lips, or paws in puddles, ditches, or ponds. Carriers often show no symptoms initially, but after about a week, fatigue, appetite loss, and vomiting may appear. Prompt veterinary care is crucial, as it targets the liver and kidneys and can be fatal.
In humans, symptoms mimic flu (incubating 4-14 days) but can escalate to kidney failure, liver damage, meningitis, or lung issues in severe cases. Antibiotics treat it effectively, though recovery may take time without lasting effects. Prevention starts with vaccinating dogs and avoiding contaminated water.
Toxocariasis stems from Toxocara canis roundworms in dogs (and cats). Puppies often get it from infected mothers in utero or by ingesting eggs. Adult worms reside in the intestines, migrating and laying thousands of eggs daily, shed in feces.
Humans contract it via unwashed produce or hand-to-mouth contact after touching contaminated soil—like playground sandpits. Children are most at risk due to play habits. Most cases are mild (fatigue, cough, tummy upset), but rare severe forms inflame the eye's retina. Regular deworming for dogs and thorough handwashing are proven preventives.
Salmonella bacteria cause salmonellosis in dogs, leading to fever, lethargy, vomiting, diarrhea, weight loss, skin issues, or rapid heartbeat—though some show none. Immunocompromised or recently antibiotic-treated dogs are vulnerable, via infected feces or raw meat.
In people, it triggers gastroenteritis: fever, diarrhea, vomiting, and cramps. Transmission occurs from touching contaminated objects. Treatment involves antibiotics and short isolation for quick recovery. Hygiene and cooking meat thoroughly minimize risks.
