Cats hold a special place in Kiwi homes - graceful, independent, and beloved companions. With more than 1.26 million cats across New Zealand and 40% of households sharing their home with at least one feline, these animals are deeply woven into the fabric of New Zealand family life.
Yet, while most cat guardians take pride in caring for their feline friends, there’s one aspect of ownership that tends to slip under the radar: what happens to all that cat poop. After looking at dog waste recently, we’re now turning our attention to cats! Cat waste comes with its own set of challenges for public health, wildlife, and the environment.
Why Cat Waste Deserves Attention
Approximately 90% of NZ owned cats have some form of outdoor access1, meaning a large portion of their faeces is left directly in gardens, parks, and soil. Even for indoor cats, what we do with the contents of the litter box matters - particularly when it comes to how waste is disposed of.
Cat faeces can harbour a range of pathogens - some with implications for human health, some for other cats, for wildlife, and others for our waterways. Understanding these risks helps cat guardians make informed, responsible choices without compromising their cats’ welfare.
1. Pathogenic risks from cat faeces
Toxoplasma Gondii – The Main Culprit
Cats are the only animals capable of shedding Toxoplasma gondii oocysts in their faeces. Once shed, these hardy oocysts can survive in soil2 and water3 for months or even years - and be washed into waterways through land-based surface runoff4.
For pregnant women and immunocompromised individuals, T. gondii can pose serious health risks, including miscarriage or illness from toxoplasmosis5. It’s also a growing wildlife concern: In New Zealand, toxoplasmosis has been identified as a significant threat to native and marine species, including Hector’s and Māui dolphins6, with infections traced to land-based runoff. The disease has been recorded as the leading cause of death in these dolphins and has also affected native species such as kiwi, kererū, kākā, and kākāriki.
Other Parasites and Public Health Risks
Cat faeces pose additional health risks beyond toxoplasmosis. Roundworm eggs (Toxocara cati) can cause toxocariasis in humans, leading to eye or organ damage7, and have been associated with disease in the North Island brown kiwi8. Hookworm larvae present in contaminated soil can penetrate human skin, causing cutaneous larva migrans with varying levels of discomfort, though such infections are rare in New Zealand. Diarrhoeal parasites including Giardia and Cryptosporidium can also be transmitted between animals and humans through faecal contamination.
Bacterial and Viral Pathogens
Cat faeces can also carry other pathogens, though these are less commonly transmitted than Toxoplasma. Bacterial contaminants include Salmonella, Campylobacter, and E. coli (including antibiotic-resistant strains), which can cause gastrointestinal illness in humans9,10,11.
Threats to other cats
While the pathogens mentioned above can affect both humans and other cats, feline panleukopenia, also called feline distemper, represents another particularly serious threat, affecting only cats and posing the greatest risk to kittens. This highly contagious virus, acting much like canine parvovirus, can be very deadly in kittens under one year of age (mortality rate over 90%)12. It is transmitted through contact with infected cats (infected body fluids or faeces) or contaminated environments, and can cause sudden, severe illness. Fortunately, vaccination offers highly effective, long-lasting protection.
2. Environmental Impacts
Cat waste poses serious contamination risks to land and water ecosystems. When cats defecate outdoors, they introduce parasites and bacteria into soil - contaminating gardens, sandpits, and children's play areas. Toxoplasma gondii oocysts are particularly concerning due to their resilience, remaining infectious in moist soil for months.
The contamination pathway extends from land to sea through stormwater runoff, which carries cat faeces into rivers and coastal waters. As we've mentioned, this creates a direct threat to marine mammals, with T. gondii infecting sea otters overseas and dolphins here in New Zealand. The problem is compounded by the fact that standard wastewater and septic systems cannot destroy these oocysts, meaning that even flushing cat litter contributes to environmental contamination.
The scale of this marine pollution is evident in New Zealand research: T. gondii DNA was detected in 16.4% of commercially sourced green-lipped mussels, with higher prevalence in summer13. The presence of viable oocysts indicates substantial coastal contamination, likely from cat-derived runoff. This poses risks not only to marine wildlife but potentially to humans consuming contaminated shellfish.
Responsible cat management is essential to reduce these cascading environmental and ecological impacts.
3. Managing Cat Waste Responsibly
Indoor Litter Box Care
The Code of Welfare for Companion Cats (MPI) provides clear recommendations:
Litter trays should be checked daily, cleared of wastes, replenished or changed as required, or double-bagged and sealed for rubbish disposal in accordance with local by-laws14. Because toxoplasmosis can be transmitted through contact with cat faeces and poses particular risks to pregnant women, precautions such as wearing gloves should be taken when cleaning litter trays.
Environmental considerations:
Clay-based and crystal (silica gel) litters have a significant environmental footprint due to their non-renewable sourcing, energy-intensive manufacturing, and persistence in landfills, making them less sustainable choices for environmentally conscious cat owners.
Plant-based or biodegradable litters made from wood, recycled paper, corn, or wheat are more environmentally sustainable choices, but they still need to be disposed of in general waste destined for landfill - not in compost or green waste bins. Do not compost cat waste for compost used in vegetable gardens or near edible plants.
Some councils are exploring municipal composting for pet waste15, but currently none of the commercial or community composting facilities in New Zealand accept pet waste and cat litter.
Best practice for cat guardians:
Scoop the litter box daily to minimise oocyst survival.
Double-bag used litter before disposing of it in household rubbish. This simple precaution contains pathogens like T. gondii, prevents leakage of urine and moisture, controls odours, and protects waste collection workers from exposure to contaminated material if bags tear during handling or transport.
Never flush cat litter or faeces - even “flushable” brands - as oocysts can survive wastewater treatment.
Don't compost cat waste for compost used in vegetable gardens or near edible plants.
Pregnant or immunocompromised individuals should avoid handling litter if at all possible.
Outdoor Companion Cat Waste Management
Cats typically bury or cover their waste for three main reasons rooted in their natural behaviour16. First, it's an instinctive behaviour inherited from their wild ancestors. Second, cats are naturally clean animals with a keen sense of smell, so they cover their waste to eliminate odours that might interfere with eating, drinking, and playing, while preventing contamination of food and water sources. Finally, burying faeces is a survival instinct that helps cats hide their scent from potential predators and threats.
However, this doesn't eliminate pathogen risks, as Toxoplasma oocysts and other pathogens can still leach into soil and reach waterways through rainfall and runoff. Most owners realistically can't pick up after their outdoor cats, but there are ways to reduce impact:
Cover sandpits when not in use.
Discourage cats from toileting in vegetable gardens with fencing or scent deterrents.
Contain cats within property boundaries or cat-proof areas where possible, particularly near sensitive habitats or waterways.
4. Why It Matters for Everyone
Proper cat waste management extends far beyond simple hygiene - it reflects the deep interconnectedness between people, pets, and the environment. Our homes and gardens sit upstream from the very waterways and coastlines that sustain both our communities and native wildlife. Through thoughtful waste management practices, we can simultaneously protect our pets' health and safeguard the ecosystems upon which we all depend.
5. Best Practice Summary
🧺 Scoop daily and double-bag waste before disposal in household rubbish
🚫 Never flush cat litter or faeces, or compost cat waste for compost used in vegetable gardens or near edible plants.
🧤 Take precautions if pregnant or immunocompromised – wear gloves when cleaning
🏠 Keep cats contained within property boundaries where possible
🌊 Protect vege gardens and sandpits from outdoor toileting
♻️ Choose plant-based or biodegradable litter material - but dispose of it safely
💉 Ensure cats are vaccinated, desexed, microchipped and registered
🐾 Promote responsible cat guardianship to protect NZ’s wildlife and waterways.
Looking Ahead
Research into safer composting methods for pet waste and innovations in sustainable cat litter products continue to evolve. Until these solutions become widely accessible, the most powerful tools we have are awareness and consistent daily action.
CANZ supports council bylaws requiring desexing of cats by 12-16 weeks, microchipping and registration on the NZ Companion Animal Register. Among many other benefits, these bylaws help prevent unwanted litters that could contribute to feral or stray populations – and further mitigate associated environmental impacts.
At Companion Animals New Zealand, we believe responsible cat guardianship extends beyond meeting our cats' immediate needs - it encompasses caring for the environment we all share. Managing cat waste thoughtfully is an essential part of this commitment, ensuring our beloved companions and the ecosystems that sustain us can both thrive together.
References
1Companion Animals New Zealand (2025): Companion Animals in New Zealand 2024. Available from: https://static1.squarespace.com/static/5d1bf13a3f8e880001289eeb/t/67c5362c18b9881a1fec4b5d/1740977787548/CANZ+2024+Pet+Data+Report-compressed.pdf
2Lélu, M., Villena, I., Dardé, M.-L., Aubert, D., Geers, R., Dupuis, E., Marnef, F., Poulle, M.-L., Gotteland, C., Dumètre, A., & Gilot-Fromont, E. (2012). Quantitative estimation of the viability of Toxoplasma gondii oocysts in soil. Applied and Environmental Microbiology, 78(15), 5127–5132. https://doi.org/10.1128/AEM.00246-12
3Dumètre, A., & Dardé, M. L. (2003). How to detect Toxoplasma gondii oocysts in environmental samples? FEMS Microbiology Reviews, 27(5), 651–661. https://doi.org/10.1016/S0168-6445(03)00066-1
4Miller, M. A., Gardner, I. A., Kreuder, C., Paradies, D. M., Worcester, K. R., Jessup, D. A., Dodd, E., Harris, M. D., Ames, J. A., Packham, A. E., & Conrad, P. A. (2002). Coastal freshwater runoff is a risk factor for Toxoplasma gondii infection of southern sea otters (Enhydra lutris nereis). International Journal for Parasitology, 32(8), 997–1006. https://doi.org/10.1016/s0020-7519(02)00069-3
5Dubey, J. P., & Jones, J. L. (2008). Toxoplasma gondii infection in humans and animals in the United States. International Journal for Parasitology, 38(11), 1257–1278. https://doi.org/10.1016/j.ijpara.2008.03.007
6Department of Conservation. (2020). Toxoplasmosis action plan: Addressing the threat of toxoplasmosis to Hector’s and Māui dolphins. June 2020. https://www.doc.govt.nz/nature/pests-and-threats/diseases/toxoplasmosis-and-hectors-and-maui-dolphin/toxoplasmosis-action-plan/
7Hartley, M. (2009). Toxocariasis — extra information. DermNet NZ. Retrieved November 10, 2025, from https://www.dermnetnz.org/topics/toxocariasis
8French, A. F., Castillo-Alcala, F., Gedye, K. R., Roe, W. D., & Gartrell, B. D. (2020). Nematode larva migrans caused by Toxocara cati in the North Island brown kiwi (Apteryx mantelli). International Journal for Parasitology: Parasites and Wildlife, 11, 221–228. https://doi.org/10.1016/j.ijppaw.2020.02.011
9Bourne, J. A., Chong, W. L., & Gordon, D. M. (2019). Genetic structure, antimicrobial resistance and frequency of human associated Escherichia coli sequence types among faecal isolates from healthy dogs and cats living in Canberra, Australia. PLoS ONE, 14(3), e0212867. https://doi.org/10.1371/journal.pone.0212867
10Te Whatu Ora. (n.d.). Campylobacteriosis – Communicable disease control manual. Retrieved November 11, 2025, from https://www.tewhatuora.govt.nz/for-health-professionals/clinical-guidance/communicable-disease-control-manual/campylobacteriosis
11Australian Companion Animal Zoonoses Advisory Panel. (2020). Companion Animal Zoonoses Guidelines. Retrieved from https://online.flippingbook.com/view/940613362/71
12Truyen, U., Addie, D., Belák, S., BoucrautBaralon, C., Egberink, H., Frymus, T., GruffyddJones, T., Hartmann, K., Hosie, M. J., Lloret, A., Lutz, H., Marsilio, F., Pennisi, M. G., Radford, A. D., Thiry, E., & Horzinek, M. C. (2009). Feline panleukopenia: ABCD guidelines on prevention and management. Journal of Feline Medicine and Surgery, 11(7), 538–546. https://doi.org/10.1016/j.jfms.2009.05.002
13Coupe, A., Howe, L., Burrows, E., Sine, A., Pita, A., Velathanthiri, N., Vallée, E., Hayman, D., Shapiro, K., & Roe, W. D. (2018). First report of Toxoplasma gondii sporulated oocysts and Giardia duodenalis in commercial green-lipped mussels (Perna canaliculus) in New Zealand. Parasitology Research, 117(5), 1453-1463. https://doi.org/10.1007/s00436-018-5832-8
14Ministry for Primary Industries. (2018, October 1). Code of welfare – Companion cats. New Zealand Government. https://www.mpi.govt.nz/dmsdocument/46021-Code-of-Welfare-Companion-cats
15Hurunui District Council. (n.d.). Discounted composting kits. Retrieved November 11, 2025, from https://www.hurunui.govt.nz/property-rates/rubbish-recycling/additional-information/bokashi-kits#:~:text=As%20pet%20waste%20should%20not%20put%20in,cycle%20of%20composting%2C%20your%20composter%20may%20never%20fill
16Hart, H. (2025, April 29). Why do cats bury their poop? PetMD. https://www.petmd.com/cat/behavior/why-do-cats-bury-their-poop