The topic of flushing pet poo is rather a murky one. The answer as to whether it's safe or not will vary depending on where you live and who you ask. For example, the Environmental Protection Agency in the USA advocates it but many other water companies here in the UK strongly advise against it. This may be due to the different water treatment processes that they use.
Despite these disparities, there are two things they do tend to agree on:
1. NEVER flush cat poo or biodegradable or 'flushable' cat litter
2. NEVER flush biodegradable/compostable or 'flushable' poo bags
Cat poo often contains a highly resistant parasite called Toxoplasma that can infect people and animals. Many municipal water treatments do not have equipment or processes to kill it (as they're designed for humans who don't poop this parasite!) meaning it would pass into our waterways, posing a risk to humans and animals alike. It can even prove fatal for some wildlife.
Many studies have shown that so called biodegradable and 'flushable' products, including flushable poo bags, don't actually disintegrate as claimed. This is primarily because they're designed to biodegrade in warm water, not cold water, like that in our toilets. In fact, 'flushable' poo bags have historically caused $8 million in blockages in Australia so it's not recommended to try flushing these bags, despite what they claim! The same goes for cat litter. Our old sewage systems are only designed for the 3 P's - Pee, Poo and Paper and can easily get blocked if anything else is thrown in.
So what about dog poo (without the bags)?
Again, dog poo is considerably different to human poo. It contains twice the harmful bacteria and viruses and also contains unique parasites. One particular parasite, Toxocara, is highly resistant to high temperatures. Our water treatment facilities are not designed to deal with dog poo pathogens such as this so there's a chance that they will pass through and contaminate our waterways if flushed down the toilet. Toxocara can also infect humans, causing blindness in children and infect animals so presents a public health risk. This is why many waste water treatment plants advise against flushing any type of pet poo down the toilet, due to the extra pathogens it contains.
Dog and cat poo can also contain medicines, such as parasite treatments, which can be highly toxic to aquatic life and may threaten the stability of entire ecosystems. Medicines are much trickier to clean from sewage and will likely pass unchanged into our waterways.
There's also the question of whether flushing pet waste could really ever be a viable widespread solution. Could our old sewage systems really cope with the additional faeces of 12 million dogs and 10 million cats if everyone starting flushing their pet's poo? It's unlikely!
We contacted Wessex Water and South West Water on the matter of flushing pet poo and both gave different answers. The former advised it was safe to do so, while the latter strongly advised against it! This may be due to their different treatment processes which can vary depending on location. However both water companies agreed that you should never flush any 'flushable' products down the toilet, even if they claim to be safe to flush as in real world this just simply isn't the case and they often cause costly blockages. They emphasised that only the three P's - Poo, Paper and Pee should ever be flushed down the toilet.
In summary, never flush biodegradable or 'flushable' poo bags or cat litter down the toilet. We also feel it's safer to avoid flushing cat and dog faeces, due to it's pathogenic content, the unknown risks of parasite treatments and medicines on wildlife and the wider environment and due to the inconsistent advice. Dog poo may be disposed in a well managed compost or wormery, rather than down the toilet. If you are still really keen to flush pet poo, make sure you speak to your local water treatment plant before you do so, as they may or may not have the treatments to safely process it.
If you dispose of your pet's waste in general waste then ensure to do so in the most eco-friendly way by using recycled poo bags such as Award Winning ReSEAcled poo bags. Experts advice it's better to re-use waste that was already destined for landfill or incineration rather than using poo bags made form virgin materials because this helps reduce plastic production, reduce plastic pollution and cuts carbon emissions and energy use. ReSEAcled poo bags are also the world's first Plastic Negative poo bags, removing 5 times as much plastic from the environment than they use! Click here to learn more.