Irish Setter laying on sofa

How do dogs get worms?

Dogs and cats become infected with worms by eating worm eggs from contaminated soil or stool, by eating infected rodents or by fleas. Hookworms are contracted by when dogs eat microscopic larvae or from larval entry through skin, usually on the feet.

What are the signs your dog has worms?

In the early stages of infection the worms stay hidden inside your dog's gut, so it may be difficult to identify early signs. Mature tapeworms start shedding egg-filled segments, which irritate the pet's bottom as they wriggle out of the anus (and may be seen as what look like ‘grains of rice’). In dogs, this causes the classic symptom of tapeworm infection - 'scooting', or dragging the bottom along the ground. Apart from this, there are few definite signs, but these may include:

  • visible worms or eggs in the faeces
  • visible worms in fur or around the dog's rear
  • scratching or rubbing of rear
  • visible worms in vomit
  • bloated stomach or belly
  • weakness, increased appetite, constant hunger and weight loss
  • diarrhoea, particularly with blood

Never forget your flea and worming treatment again. 

What type of worms are there?

There are six types of worm that generally affect dogs:

  • heartworm
  • roundworm
  • hookworm
  • tapeworm
  • whipworm
  • lungworm

What harm can worms do?

Depending on the worm, an infestation can have a range of effects, from weight loss, exercise intolerance, general malaise and in some rare cases, even sudden death.

How do I treat my dog for worms?

There are various types of wormer available, some are tablets and some are spot-on treatments. Ideally, seek advice from your vet to select a wormer that kills multiple species of worm.

How often should I treat my dog for worms?

At least every three months. Depending on your pet's lifestyle, more regular worming may need to be undertaken and it is recommended this be discussed with your vet if you are concerned. 

How can I prevent my dog getting worms?

All dogs will carry worms. When you use a worming product it does not eradicate all worms, it reduces the worm burden, preventing worms from taking over. Regular worming treatment is essential for your pet's overall health.

Are there any risks to me?

Certain worms are capable of being transmitted from animals to humans. Such worms are said to have a 'zoonotic potential'. The dog roundworm, Toxocara canis, is the best known of these (but the cat roundworm T. cati can also be responsible) and human infection may occur if a person swallows the microscopic worm eggs, having picked them up from contaminated soil, with small children being at the greatest risk.

The larvae of the roundworm do the damage to health as they migrate through the body from the gut. They can arrive, for example, in the eye, causing permanent damage to sight.

Author article

This article was written by Luke Gamble, CEO of WVS and Mission Rabies and star of Sky One's Vet Adventures who has given The Kennel Club kind permission to replicate this article.

Think your dog may be affected?

If you're worried about your dog's health, always contact your vet immediately!

We are not a veterinary organisation and so we can't give veterinary advice, but if you're worried about any of the issues raised in this article, please contact your local vet practice for further information.

Find a vet near you

If you're looking for a vet practice near you, why not visit the Royal College of Veterinary Surgeons' Find a vet page.