Roundworm (Toxocara canis)

Overview

The most common intestinal worm of dogs worldwide and near-universal in unwormed puppies. Puppies are typically infected from their mother — across the placenta before birth and through her milk after it — which is why worming starts in the first weeks of life and why worming the bitch is not sufficient. It matters beyond the dog: Toxocara is zoonotic, and eggs shed in faeces contaminate soil and public parks, where children can ingest them, with rare but serious consequences for the eyes and other organs. That makes routine worming and picking up faeces a public-health act, not only a courtesy. Diagnosis is by faecal examination; treatment is a routine anthelmintic class on a schedule the vet sets, and prevention is a lifelong deworming programme (see the parasite-control section).

What you would notice

• Pot-bellied puppy with a dull, staring coat
• Spaghetti-like white worms in vomit or stool
• Poor growth despite a good appetite
• Intermittent diarrhoea, sometimes with coughing in heavy infections
• Adult dogs often show nothing at all while still shedding eggs

Sources

• Merck Veterinary Manual (merckvetmanual.com)
• WSAVA global guidelines (wsava.org)
• Indian Council of Medical Research (icmr.gov.in)

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