Intestinal worms: types, exposure & protection

Worms are not one condition

Roundworms such as Toxocara canis can affect puppies and adults; exposure includes contaminated environments and, for puppies, transmission from the mother. Tapeworms have different routes: Dipylidium is linked to swallowed infected fleas, while other species involve prey, raw offal or carcasses. Hookworms can cause intestinal disease and some species significant blood loss. Whipworms live in the large intestine and may cause diarrhoea. Species and prevalence vary geographically.

Signs can be absent

A dog may carry worms without obvious signs. Possible changes include diarrhoea, weight loss, reduced condition or visible worm segments. These are not specific enough to diagnose infection. A sick puppy, bloody stools, weakness or persistent vomiting needs prompt veterinary advice rather than an over-the-counter trial alone.

Make an individual control plan

Tell your practice about age, travel, scavenging, hunting, raw food, household contacts and previous treatment. Ask whether testing, treatment or both are appropriate, and which parasites the product covers. A stool result has limits: timing, sampling and parasite type affect what is detected. A negative result does not rule out every parasite, particularly those outside the intestine.

Protect people and the environment

Some worm infections can affect people. Pick up faeces promptly, wash hands and prevent access to carcasses or raw offal. Supervise children around contaminated soil. Use age- and weight-appropriate products as advised; not every wormer covers tapeworm, lungworm or heartworm. See lungworm and geographical differences.

Continue your care plan

Parasites & Preventative Healthcare · Keeping my dog healthy · New symptoms: find the right next step

Evidence and review

General information, not diagnosis or an individual treatment plan. Sources include veterinary professional guidance, veterinary charities and relevant regional parasite organisations. Clinical recommendations need individual veterinary interpretation.

• ESCCAP UK & Ireland: worm species and exposure
• ESCCAP: worm-control guidance
• CPEP / University of Saskatchewan: intestinal nematodes
• CPEP / University of Saskatchewan: tapeworms

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