External Parasites


Fleas are a year round problem in Northland. In warmer months flea stages in the environment develop quickly leading to large population explosions, while in colder months the cycle slows down but does not stop. We recommend the regular use of a good quality vet approved flea treatment all year round as the most successful approach to flea control in the home.

The majority of the flea population lives off the pet in the form of eggs, larvae and pupae in the environment where cats and dogs roam and rest. The adult fleas that you are seeing on your animals make up only about 5% of the actual flea population present. The remaining 95% is made up of eggs, larvae and pupae. Pets acquire fleas from the environment where other animals have been such as the garden, the park or neighbouring properties. It is very rare for a flea to jump from animal to animal.

Flea pupae exist in the environment and when the conditions are favourable they hatch, jump onto your pets and 24 hours later are laying eggs. Pupae are stimulated to hatch by warmth, vibration, shadow and carbon dioxide – these conditions signal that a suitable host is within reach. In favourable conditions it can take up to three weeks to break the lifecycle completely and gain control over a heavy environmental infestation.

Regular vacuum cleaning including under furniture and hard-to-reach places greatly reduces pet reinfestation via the environment and helps to reduce a population explosion in the warmer months. The vacuum cleaner dust should be disposed of daily.

Did you know?

Fleas seen on your pet today may have been eggs laid up to 6 months ago.

Cats are often found to be the cause of continual reinfestation in dogs so all pets in the household must be treated for effective flea control.

Untreated visiting pets are walking egg spreaders – a female flea can lay 50 eggs per day and these eggs are designed to drop off the animals into the environment to develop into pupae and await the next host.

Hedgehogs, rats, mice and possums are responsible for the spread of flea infestations in the garden, compost heaps and under flax bushes etc. These are often places that cats and dogs also like to visit and rest in.


The tick present in New Zealand is the New Zealand cattle tick (Haemaphysalis longicornis). Ticks are generally found in long grass grazed by cattle and affect a number of animals including both cats and dogs.

Your pet can pick up ticks by wandering through grass. Ticks are generally seen during the warmer months from August to April but can be seen all year round in Northland.

Ticks suck blood and can cause irritation to you and your pets.

There are a number of flea treatments on the market that are also effective against ticks.


There are several mites present in New Zealand which can cause problems in both cats and dogs. They are generally too small to be seen by the naked eye so require a clinic visit to diagnose. Several of the flea products on the market are also active against mites.

Internal Parasites

Intestinal Worms

Adult cats and dogs should be treated routinely for intestinal worms every 3 months with an all wormer that is effective against both tapeworms and roundworms.

Lung Worm

Lung worm is a parasite of cats. It is commonly seen in cats with outdoor access and especially in hunting cats. Lungworms live in the lungs and cause irritation resulting in a moist cough. If untreated it can worsen and cause severe respiratory disease. Several of the flea treatment products available at The Vet Centre will treat lungworm so talk to us about your options.