For most New Zealand families, the backyard is where kids play, pets roam and weekend barbecues happen. But if you have a dog, there is an invisible health risk lurking in every pile of waste left on the lawn. Dog faeces carry a range of parasites and bacteria that can cause serious illness in children, adults and other animals — and the risks are far more significant than most people realise.
In this guide, we break down the specific health threats found in dog waste, explain why children are particularly vulnerable and outline what you can do to keep your family safe.
The Parasites Hiding in Dog Waste
Dog faeces are not just unpleasant — they are a breeding ground for parasites that can survive in your soil long after the visible waste has disappeared. Here are the main culprits New Zealand families need to know about.
Roundworm (Toxocara canis)
Roundworm is one of the most common intestinal parasites found in dogs, particularly puppies. A single roundworm can produce up to 200,000 eggs per day, and these eggs are shed through the dog's faeces into your backyard soil. The eggs are remarkably hardy — they can survive in soil for several years, even through Auckland's wet winters and warm summers.
When a child ingests roundworm eggs (which can happen simply by playing in contaminated soil and then touching their mouth), they can develop a condition called toxocariasis. This disease has two main forms:
- Visceral larva migrans (VLM): The larvae migrate through internal organs, causing fever, fatigue, coughing, abdominal pain and wheezing. In severe cases, it can affect the liver and lungs.
- Ocular larva migrans (OLM): The larvae travel to the eye, where they can cause inflammation, vision impairment and, in rare cases, permanent blindness in the affected eye.
New Zealand has documented cases of toxocariasis in children, and studies have found Toxocara eggs in soil samples from public parks across the country. Children aged one to five are most at risk because of their tendency to play in dirt and put their hands in their mouths.
Hookworm
Hookworm larvae are particularly insidious because they do not need to be swallowed to cause infection. The larvae can penetrate human skin directly — typically through bare feet walking on contaminated ground. This causes a condition called cutaneous larva migrans, characterised by intensely itchy, raised red tracks that wind across the skin.
In Auckland's warmer months, when children and adults are more likely to be barefoot in the garden, the risk increases significantly. Hookworm larvae thrive in warm, moist conditions — exactly the kind of environment you find in a shaded Auckland backyard during summer.
Giardia
Giardia is a protozoan parasite that causes giardiasis, a nasty gastrointestinal illness characterised by severe diarrhoea, cramping, nausea and dehydration. It is highly contagious between dogs and can readily infect humans, particularly children and people with weakened immune systems.
Giardia cysts can survive in moist soil and water for months. In Auckland's humid, temperate climate — from suburbs like Mt Eden and Remuera through to the leafy sections of Titirangi and the North Shore — conditions are ideal for Giardia to persist in the environment.
Cryptosporidium
Cryptosporidium is another protozoan parasite that causes watery diarrhoea and is resistant to many common disinfectants. It spreads through contaminated water, which is why dog waste near garden taps, paddling pools or drainage areas is particularly concerning for families with young children.
Bacterial Threats in Dog Waste
Beyond parasites, dog faeces contain dangerously high levels of bacteria. Research shows that a single gram of dog waste contains an average of 23 million faecal coliform bacteria. Key bacterial threats include:
- E. coli: Can cause severe gastrointestinal illness, particularly dangerous for children under five
- Salmonella: Causes food poisoning symptoms including vomiting, diarrhoea and fever
- Campylobacter: One of the most common causes of gastroenteritis in New Zealand, with over 6,000 cases reported annually
These bacteria do not remain on the surface. Rainfall washes them into the soil, and they can persist for weeks or months. Every time children play on the grass, crawl on the lawn or dig in the garden, they risk exposure.
Why Children Are Especially Vulnerable
Children face a disproportionately high risk from dog waste contamination for several reasons:
- Hand-to-mouth behaviour: Young children constantly put their hands, toys and other objects in their mouths after touching contaminated surfaces
- Ground-level play: Babies and toddlers crawl, roll and sit directly on grass and soil
- Developing immune systems: Children's immune systems are not fully mature, making them more susceptible to infection
- Curiosity: Young children may directly handle animal waste before a parent can intervene
- Bare feet: Kiwi kids are famously barefoot, increasing the risk of hookworm penetration through the skin
Protecting Your Pets Too
It is not just humans at risk. Dogs that come into contact with contaminated faeces — whether their own from previous deposits or from visiting dogs — can reinfect themselves or contract new parasites. Puppies are particularly vulnerable, and heavy parasite loads can cause serious illness, weight loss and developmental issues in young dogs.
Regular worming treatments help, but they are not a substitute for removing the source of contamination from your yard. A clean backyard combined with a veterinary worming schedule is the most effective approach.
How Regular Cleanup Protects Your Family
The single most effective way to reduce health risks from dog waste is regular, thorough removal. Here is why frequency matters:
- Roundworm eggs take 2-4 weeks to become infectious after being deposited. Weekly removal means most eggs are collected before they reach the infectious stage.
- Bacterial levels in soil decrease significantly when waste is removed promptly rather than left to decompose.
- Parasite cyst accumulation is prevented when waste does not build up over time.
- Fly breeding cycles are disrupted — flies are a secondary vector for spreading bacteria from waste to food and surfaces.
A weekly cleanup routine — whether you do it yourself or use a professional service — is the minimum recommended frequency for households with dogs and children. For multi-dog households, twice-weekly may be more appropriate.
Practical Steps for Auckland Families
Here are some practical measures to minimise health risks from dog waste in your backyard:
- Clean up at least weekly: Do not let waste accumulate. The longer it sits, the greater the risk.
- Wash hands thoroughly: Ensure children wash their hands with soap and water after playing outside, especially before eating.
- Keep worming treatments current: Follow your vet's recommended worming schedule for all dogs in the household.
- Designate a toilet area: If possible, train your dog to use a specific area of the yard away from where children play.
- Wear shoes in the garden: Encourage footwear in areas where dogs toilet to reduce hookworm risk.
- Rinse outdoor toys regularly: Balls, bikes and garden toys that sit on the lawn can harbour bacteria.
Let Us Handle the Dirty Work
Keeping your backyard safe for your children and pets does not have to be a chore you dread. At Backyard Buddies, we provide regular, thorough dog waste removal across Auckland — so your family can enjoy the backyard without the health risks.
Get a free instant quote and see how easy it is to protect your family with a cleaner, safer backyard.