Worms in Cats and Dogs

Worming is one of those quiet care jobs that is easy to overlook. Eggs and larvae can be carried in soil, faeces, prey and fleas, while some adult worms live inside a pet without causing obvious early signs. A regular routine protects your pet and helps reduce contamination around the home, garden and places where pets exercise.

This guide focuses on parasites relevant to cats and dogs in New Zealand. Overseas advice can include different risks, so it is worth checking that recommendations match local conditions.

Which worms affect dogs in New Zealand?

Roundworm

Roundworms live in the intestine. Puppies can be exposed through their mother, and dogs can also pick up infective eggs from contaminated ground. A heavy burden may contribute to a pot-bellied appearance, poor growth, digestive upset or a dull coat, although some dogs show no obvious signs.

Hookworm

Hookworms attach to the intestinal lining and feed on blood. Dogs can be exposed through contaminated environments, and young dogs can become unwell more quickly than healthy adults. Pale gums, weakness, dark stools or poor growth need prompt attention.

Whipworm

Whipworm is a dog parasite that lives in the large intestine. Its eggs can persist in the environment, which makes consistent clean-up and an appropriate worming plan important. Diarrhoea, straining and weight loss can occur when burdens are significant.

Tapeworm

Dogs can acquire flea tapeworm by swallowing an infected flea while grooming. Other tapeworm risks are linked to scavenging or access to raw offal. Rice-grain-like segments around the bottom or bedding can be a clue, but their absence does not rule tapeworm out.

Which worms affect cats in New Zealand?

Roundworm

Cats can pick up roundworm eggs from contaminated environments or acquire infection by hunting. Kittens and outdoor cats may have more exposure, but indoor living does not remove every route because eggs can be carried inside on shoes or objects.

Tapeworm

Flea tapeworm is linked to swallowing infected fleas. Hunting rodents can create another route of exposure. This is why flea control and worming should be planned together rather than treated as unrelated jobs.

Lungworm

Cat lungworm is present in New Zealand and can be associated with hunting and intermediate hosts such as slugs, snails, birds or rodents. Coughing or breathing changes should not be assumed to be worms, but they do need timely assessment.

What about heartworm?

Heartworm is not present in New Zealand. Some broad-spectrum products sold here include heartworm coverage because they are also used in countries where it occurs. If your cat or dog will travel overseas, ask your vet for a destination-specific prevention plan before departure.

Signs that may be linked with worms

• Worms or rice-like segments in faeces, around the bottom or on bedding
• Diarrhoea, vomiting, straining or a change in appetite
• Weight loss, poor growth or a pot-bellied appearance
• A dull coat, reduced energy or pale gums
• Coughing or breathing changes in a cat, which can have many causes

These signs are not specific to worms. Puppies, kittens and pets that are weak, pale, repeatedly vomiting, struggling to breathe or passing blood need prompt professional assessment rather than another dose given without guidance.

How often should cats and dogs be wormed?

A common guide is to worm puppies and kittens every two weeks from 2 to 12 weeks of age, monthly from 12 weeks to 6 months, then every three months for many typical-risk adult pets. This is a starting point rather than one schedule for every household. Hunting, scavenging, raw meat or offal, flea exposure, farm living, travel and living with young children or immunocompromised people can change the plan.

Always follow the dose, minimum age and interval on the current product label. Do not assume that a flea product also covers worms, or that an allwormer covers every flea and tick risk. If switching products, compare active parasite coverage so that a gap is not created accidentally.

1. Record your pet's current weight and choose a product labelled for their species and weight range.
2. Check exactly which worms the product covers, including whether tapeworm is included.
3. Follow the labelled dose, minimum age and repeat interval.
4. Set a reminder and keep flea control current to help interrupt flea tapeworm.
5. Review the plan after travel, a move, a new pet, a change in hunting habits or a missed dose.

Worming options to compare

Compare cat and dog wormers by species, weight, format and parasite coverage. Look for each worm by name, including tapeworm, and treat the current New Zealand packaging and label as the source of truth.

Reduce reinfection around the home

• Pick up dog faeces promptly and clean litter trays daily to reduce contamination from worm eggs.
• Wash hands after handling waste, soil or pet bedding, and help young children do the same after outdoor play.
• Keep flea prevention current for every suitable pet in the household.
• Discourage scavenging and access to raw offal.
• Wash bedding and clean shared sleeping areas regularly.

Related reading

Worming Your Dog in NZ

Best Dog Worm Treatments in New Zealand

Best Cat Worm Treatments in New Zealand

How to Create a Flea-Free Home

How to Choose the Right Flea Treatment

How to Spot Flea Dirt