Public Health Asks Can People Catch Hookworms From Dogs

Is Your Dog Off the Hook? Maybe Not, If It's A Greyhound-Persistent

For decades, the question lingered in public health circles: can humans actually contract hookworms from domestic dogs? It’s not a simple yes or no—it’s a matter of exposure, biology, and behavior. The reality is, while hookworm transmission to humans is rare, it’s not impossible. This leads to a larger problem: how do we accurately assess risk when laypeople, veterinarians, and public health officials speak different languages about zoonotic threats?

The hookworm species *Ancylostoma caninum* is primarily adapted to dogs, distinct from the more common *Ancylostoma braziliense*, which infects both animals and humans. Yet, *A. caninum* can survive briefly outside a host, lingering in warm, moist soil—conditions often created when infected dogs defecate near human footwear, play areas, or latrines. A 2022 field study in rural Kenya found that *A. caninum* larvae persist for up to 60 days in shaded ground, a critical window for accidental human contact.

Direct transmission is uncommon: Unlike roundworms or tapeworms, hookworms don’t easily penetrate intact human skin. Infection typically requires larvae to breach a cut—think barefoot walking through contaminated sand or soil. A single barefoot stroll through a dog’s soiled yard isn’t a guarantee, but repeated exposure dramatically increases risk.
Environmental persistence matters: The larvae’s ability to survive outside a host hinges on humidity and temperature. In tropical climates, with daily highs above 25°C and humidity exceeding 80%, larvae remain viable for weeks—far longer than in temperate zones. This explains why hookworm hotspots in humid regions correlate with higher canine infection rates.
Human cases are rare but measurable: Globally, human hookworm infections are estimated at over 500 million, but only a fraction are linked to dogs. A 2019 outbreak in northern Brazil traced 37 cases to contact with contaminated soil near dog-infested informal settlements—proof that context and living conditions amplify risk.
Diagnostic ambiguity complicates data: Many suspected cases go unreported or misdiagnosed due to overlapping symptoms—dermatitis, fatigue, anemia—leading public health systems to underestimate the true burden. Without precise molecular testing, distinguishing *A. caninum* from other hookworms remains a challenge.

Veterinarians and epidemiologists agree: the risk isn’t zero, but it’s highly contextual. A child playing barefoot in a clean, dry yard faces negligible exposure. A person digging in soil where dogs defecate weekly? That’s a different story. The CDC stresses that while zoonotic hookworm transmission is not a daily threat, it’s a real one—especially in communities with poor sanitation and high dog population density.

This isn’t just about biology—it’s about public health messaging. Overly alarmist warnings fuel unnecessary fear, while downplaying the risk leaves vulnerable populations exposed. The solution lies in nuanced education: teaching foot protection, proper soil decontamination, and routine soil testing in endemic zones. It’s not about blaming dogs, but about understanding the invisible thread connecting animal health and human safety.

In the end, the hookworm question reveals a deeper truth: public health thrives not on absolutes, but on precision. The science shows transmission is possible—but preventable. Awareness, not panic, is the most effective defense.