Worms That Humans Can Contract from Dogs
Humans can contract several types of worms from dogs, primarily through fecal-oral transmission or contact with contaminated soil, including tapeworms (Dipylidium caninum, Echinococcus species), roundworms (Toxocara canis), and hookworms (Ancylostoma species). 1, 2, 3
Common Zoonotic Worms from Dogs
Roundworms (Toxocara canis)
- Most commonly responsible for visceral larva migrans and ocular larva migrans in humans 2
- Transmission occurs when humans (especially children) ingest infective eggs from:
- Contaminated soil or surfaces
- Unwashed hands after petting infected dogs
- Clinical impact:
- Can migrate to various organs including eyes, brain, liver, and lungs
- Risk of permanent visual, neurological, and tissue damage
- Often presents with persistent eosinophilia
- Children at higher risk due to play habits and attraction to pets 3
Tapeworms
Dipylidium caninum
Echinococcus species
- E. granulosus: Causes cystic echinococcosis with voluminous cysts in various organs
- E. multilocularis: Causes alveolar echinococcosis, primarily affecting the liver
- Transmission occurs when humans ingest eggs shed in dog feces
- E. multilocularis infection can be lethal if untreated 3
- Dogs with access to rodents in endemic areas pose significant risk 5
Hookworms (Ancylostoma species)
- A. caninum (dog hookworm) and A. ceylanicum can infect humans 6, 7
- Transmission occurs when:
- Larvae penetrate bare skin (e.g., feet) in contact with contaminated soil
- Humans walk barefoot on contaminated ground
- Can cause cutaneous larva migrans ("creeping eruption") with skin irritation and itching
- Intestinal infection in humans is rare but possible 2, 7
Risk Factors for Human Infection
- Direct contact with infected dogs, particularly puppies 2, 3
- Poor hygiene practices after handling dogs
- Walking barefoot in areas contaminated with dog feces
- Children playing in areas where dogs defecate
- Geophagy (soil eating) is a significant risk factor for toxocariasis 3
- Dogs with hunting behavior or access to rodents (for Echinococcus) 5
Prevention Strategies
- Regular deworming of dogs, especially:
- Puppies
- Pregnant and nursing dogs
- Hunting dogs 3
- Proper disposal of dog feces to reduce environmental contamination
- Hand washing after contact with dogs or potentially contaminated environments
- Preventing children from playing in areas where dogs defecate
- Keeping dogs from hunting or consuming wild rodents in Echinococcus-endemic areas
- Educating pet owners about zoonotic risks and prevention measures 3
Treatment Considerations
For dogs with tapeworm infections, effective medications include:
- Praziquantel (drug of choice for Echinococcus and Dipylidium) 5, 4
- Mebendazole, fenbendazole, niclosamide, and bunamidine for various tapeworm species 4
For humans with confirmed parasitic infections, prompt medical treatment is essential to prevent complications related to morbidity, mortality, and quality of life impairment.
Human Medical Insights:
- Infections may be asymptomatic or cause serious disease depending on parasite load and location
- Children are at higher risk due to behavioral factors and developing immune systems
- Early diagnosis and treatment are crucial to prevent long-term complications
Human health protection should be prioritized through comprehensive pet parasite control and good hygiene practices.