Cutaneous larva migrans: the zoonosis that starts in your yard's sand
It is Brazil's most visual zoonosis: it appears on beaches, playground sandpits and yards with dog and cat feces. This guide explains the cycle, how the larva enters the skin, treatment in pets and humans, and the measures that cut transmission at the source.
Information, not diagnosis. This guide is educational content reviewed by CFMV-registered veterinarians. It does not replace an in-person consultation. If your pet shows the emergency signs listed here, go to a veterinary hospital now.
🚦 Urgency triage: yellow vs red flag
🟡 Yellow flag — monitor / vet in 24-72h
- An itchy red trail on a human: dermatologist within days
- A dog with mild anemia
🔴 Red flag — emergency NOW
- A puppy with pale gums and dark stools
- A child eating soil with abdominal pain and fever
The cycle: from yard feces to the trail on skin
The hookworm (Ancylostoma caninum and braziliense) lives in the dog and cat intestine and sheds eggs in feces. On warm, moist sand or soil the eggs hatch into larvae that wait for skin contact — bare feet, a child's hands in the sandbox, the belly of a dog lying on the ground. In human skin the larva cannot reach the bloodstream (we are the wrong host): it crawls under the epidermis, leaving the serpiginous red trail that names the disease, with itching that worsens at night.
In dogs and cats the adult worm lives in the gut and causes anemia — the picture our worms page details. The link between the two: feces in the environment. Every pile picked up the same day breaks the cycle.
Treatment: in pets and in humans
In pets, treatment is the right veterinary dewormer for hookworms (fenbendazole, milbemycin and others), repeated per the scheme — the dewormer page carries the calendar. In humans, cutaneous larva migrans is treated by a dermatologist with oral ivermectin or albendazole, and the trail disappears within days. Don't squeeze it, burn it or use home remedies: the larva dies with the right medication and the itch is managed with antihistamines.
The pediatric note: a child with a trail on the foot means contaminated sand — and a child who eats soil needs evaluation for visceral larva migrans, the deep version of the same zoonosis.
Prevention that cuts transmission at the source
- Pick up dog and cat feces the same day, inside and outside the house
- Deworming on a calendar (see the dewormer guide) — larvae only come from adult worms
- Cover playground sandpits when not in use
- Sandals on beaches, dirt fields and gardens with exposed soil
- Wash children's hands after the playground and keep pets away from edible vegetable gardens
What happens in the body
Entender o mecanismo da Cutaneous larva migrans muda a decisão do tutor: saber o que piora e o que alivia transforma o dia a dia em parte do tratamento, não só a ida ao veterinário.
Na ficha clínica, Cutaneous larva migrans aparece como Zoonosis — treatable. Guarde essa informação: ela decide entre 'marcar consulta' e 'ir agora'.
Common mistakes
- Waiting to see if it passes on its own with a sign that already lasts days
- Using leftover medicine from another pet or from human use
- Changing the treatment on your own mid-course
- Not bringing daily notes to the appointment
Measuring progress without frustration
No manejo de Cutaneous larva migrans, o progresso se mede em semanas, não em dias. Marque no calendário a reavaliação e escolha 2-3 indicadores simples (dor ao toque, frequência das crises, disposição no passeio) para acompanhar sempre do mesmo jeito.
O maior risco do tratamento de Cutaneous larva migrans é abandonar cedo o que funciona devagar. Antes de mudar o plano, dê a ele o intervalo que o veterinário definiu; mudança sem intervalo não permite ler resultado nenhum.
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Frequently Asked Questions
Does cutaneous larva migrans go away on its own?
The human larva dies within weeks to months without treatment, but the itching and the risk of scratched-trail infection make treatment the sensible route.
Is cutaneous larva migrans contagious between people?
No. The larva comes from the environment (sand and soil with dog and cat feces) and does not pass between humans.
Can my dog transmit it without visible worms?
Yes: eggs are shed in feces and hatch on the ground. A seemingly healthy, undewormed dog transmits — which is why the deworming calendar is public health.
Is human treatment quick?
Yes: oral ivermectin or albendazole, usually a short course, with the trail and itch regressing within days. The dermatologist confirms the diagnosis clinically.
How severe is Cutaneous larva migrans?
Cutaneous larva migrans is classified as: Zoonosis — treatable. That rating sets how fast you need care; severe cases have no safe waiting period at home.