By Dial A Vet Veterinary Team
Almost every puppy is born with roundworms, or picks them up from its mother's milk in the first weeks of life. That is not a sign of poor care. It is how the most common dog roundworm, Toxocara canis, is designed to survive. Left untreated, a heavy burden can stunt growth, cause vomiting and diarrhoea, and occasionally block the intestine. Roundworm eggs are also a health risk for children. The good news is that a simple, early and regular worming schedule, planned with your vet, keeps puppies and families safe.
Key takeaways
- Toxocara canis passes from mother to puppies before birth and through milk.
- Puppies are commonly wormed every two weeks from two weeks of age until 12 weeks, then monthly until six months.
- Signs include a pot belly, dull coat, poor growth, diarrhoea and spaghetti-like worms in vomit or poo.
- A puppy that is weak, bloated and vomiting, or not passing poo, needs a vet urgently.
- Roundworm eggs can infect people, especially young children, so hand washing and poo pick-up matter.
How puppies get roundworms
Many adult dogs carry dormant roundworm larvae in their tissues. During pregnancy, hormonal changes wake these larvae, which cross the placenta into the puppies and also pass into the milk. Puppies can therefore have adult worms laying eggs from around two to three weeks old. Puppies also pick up eggs from contaminated environments, and dogs can be infected by eating rodents or birds that carry larvae. A second species, Toxascaris leonina, is less common and does not pass through the placenta or milk.
Signs of roundworms in puppies
- Pot-bellied appearance, often with thin limbs and back
- Poor growth compared with littermates
- Dull, rough coat
- Soft stools or diarrhoea
- Vomiting, sometimes with long, white or cream worms that look like spaghetti
- Worms in the poo, especially after worming
- Coughing while larvae travel through the lungs
- Bloating or discomfort after eating
When to see a vet
Emergency now: a puppy with a swollen, tight belly that is vomiting repeatedly, not passing faeces, weak, cold or collapsed. Heavy worm burdens can cause intestinal blockage. Very young puppies also dehydrate quickly with vomiting or diarrhoea.
Same day: a puppy with diarrhoea for more than a day, that is quiet or not eating, has blood in the poo, or has a cough with fast breathing.
Book a visit: a bright puppy with a pot belly, dull coat or worms seen in poo. Bring a sample.
What to do at home
- Ask your breeder or shelter exactly when and with what your puppy was last wormed, and share this with your vet.
- Weigh your puppy regularly. Worming products are given by weight and puppies grow fast.
- Use only products labelled for puppies of your pup's age and weight, and follow the label.
- Pick up poo straight away and bin it.
- Wash children's hands after playing with the puppy and before eating. Discourage face licking.
- Cover sandpits when not in use.
How vets diagnose and treat roundworm
Vets diagnose roundworm by seeing worms or finding eggs on a faecal flotation test. Because puppies may be infected before eggs appear, vets usually recommend treatment on schedule regardless of test results.
Treatment uses a worming product effective against roundworms, repeated at regular intervals. Each treatment kills adult worms in the gut, but larvae still migrating through tissues are not all affected, which is why repeated treatment matters. After worming, it is normal to see dead or dying worms in the poo for a day or two. Puppies with heavy burdens or blockage may need hospital care. Your vet can also advise on worming the mother during pregnancy and nursing.
A typical worming timeline
Common Australian advice is to worm puppies every two weeks until 12 weeks of age, then monthly until six months, and then every three months for life, unless your vet recommends otherwise for your situation. Many monthly combination products cover roundworm along with other parasites. Talk to your vet about which product suits your puppy and whether heartworm, flea and tick protection should be included. Our overview of puppy parasites covers the broader picture.
Roundworm and people
If a person swallows infective Toxocara eggs, larvae can migrate through the body. This is called toxocariasis. It is uncommon, but it can affect the eyes and occasionally cause vision loss, and children are most at risk because of play in soil and sandpits. Eggs need a few weeks in the environment to become infective, so prompt poo pick-up greatly reduces risk. See your GP if you have any concerns.
FAQ
My puppy was wormed but I still saw worms. Is the treatment not working?
Seeing worms passed in the day or two after worming is common and expected. If you keep seeing worms after that, speak to your vet.
Can adult dogs get roundworm?
Yes, but they are less likely to have a large burden. Regular worming is still recommended.
Do I need to worm my puppy if it lives indoors?
Yes. Puppies are usually infected before birth or through milk, regardless of where they live.
Are roundworms the same as heartworm?
No. Heartworm is spread by mosquitoes and lives in the heart and lung vessels. It needs separate prevention.
Talk with a vet
New puppy and unsure where you are up to with worming? A Dial A Vet consult can help you set a schedule and choose suitable products. A bloated, vomiting or collapsed puppy needs an in-person emergency vet now.
References
- Companion Animal Parasite Council (CAPC): Ascarid (Roundworm) Guidelines
- Merck Veterinary Manual: Roundworms in Small Animals
- RSPCA Australia Knowledgebase: How often should I worm my dog?
- Centers for Disease Control and Prevention: Toxocariasis
Disclaimer: Educational only. This page does not replace an examination or advice from your own veterinarian. Always follow the label and your vet's advice when using parasite products.
