There are some things we can universally agree are quite disgusting. Chewing with your mouth open, the smell of the black bins… oh, and stepping in dog poo! Seriously, it’s 2021! Surely we shouldn’t have to be dealing with dog mess on our pavements? But why is not cleaning after your dog such a problem? Is it just because it’s revolting? Or are there more serious concerns?

So Why is it a Problem to Not Clean up After Your Dog?

The Obvious

Let’s get the obvious reason why dog poo on pavements is such a problem. It’s dirty and smelly! No one wants to have something sticky and smelly stuck on their shoe and then walked into their carpets. We can’t avoid stepping outside, so it’s only fair that dog owners do their part to minimise mess where they can. British mud and rain is already enough, thank you.

Humans and Bacteria

You probably already know that faeces is full of bacteria. We should wash our hands after going to the toilet to avoid spreading them around. Dog poo is no exception, and having it stepped in then introduced into the home increases the chance of accidental ingestion. (Yes, unfortunately, most disease from dog poo comes from accidentally eating it….)

There are potentially a huge number of bacteria found in dog mess; from the classic Salmonella and Campylobacter to nasty E. coli and even Yersinia of Black Death fame, though thankfully not the same species! These bacteria are common causes of vomiting and diarrhoea sicknesses. These kinds of illnesses can be mild, but in some cases severe or even life threatening. For certain people in particular, namely children, the elderly, and anyone immunocompromised, the risk is greatest. And remember that dogs can carry these bugs without showing any signs of sickness themselves. So it’s not just sick dogs that you have to be careful with their poo.

To make matters worse, one study has found that dog poo in city streets has the potential to harbour antibiotic-resistant bacteria, including MRSA

These bacteria are difficult or impossible to treat with common antibiotics, meaning that a person infected with them may not be able to be treated in hospital. The origin of these resistant bacteria is in part due to the misuse of antibiotics in veterinary medicine. Historically, vets haven’t been great at minimising unnecessary use of antibiotics, though we are getting better.

It is important to mention that dogs on raw food diets shed a considerable amount more bacteria than dogs on normal diets, as demonstrated in multiple studies. This is due to the bacteria in the food not being destroyed by cooking. This means that dog poo from dogs on raw diets are more contaminated and a greater risk to people. Raw feeding should always be done cautiously, under guidance of a vet for medical reasons. We recommend avoiding raw feeding in households with children or anyone immunocompromised.

Dogs and Bacteria and Viruses

Unfortunately, some dogs have a naughty habit of being interested in, smelling and even eating other dogs’ poop! This leaves them vulnerable to similar bacterial infections as well, as well as certain viruses. As in humans, they tend to affect the young, elderly and immunocompromised, causing diarrhoea and sickness. It is easy for dogs to become infected as they smell and eat other dog’s poop.

Viruses, in particular, can be especially nasty. One is parvovirus, a virus that causes severe bloody diarrhoea, vomiting, dehydration, shock and even death. We’ve seen one too many puppies with this terrible disease – treatment at the vets is difficult and not always effective. The risk is reduced by vaccinating against parvovirus (more on this later), but it is always present. Another is canine coronavirus (not that coronavirus!) which causes similar, but usually milder disease. Cleaning up faeces in the environment will help protect these vulnerable dogs from these two viruses, as well as the bacteria mentioned above.

Dogs and Parasites

Unfortunately, bacteria and viruses aren’t the only microorganisms that inhabit dog poo. Parasites also live in a dog’s intestines and can be shed in faeces. In fact, this is the primary way most are transmitted. 

Cryptosporidium and Giardia are two protozoan parasites that are commonly found in the intestines as commensals, or normal gut flora. However, they can become pathogenic and cause disease, again in vulnerable dogs. Crypto tends to cause mild diarrhoea for a few weeks and can resolve by itself. Giardia can cause the same, but is also responsible for some chronic diarrhoea issues. Sometimes dogs can be infected with both parasites, making disease worse! Diagnosing these is tricky, so avoiding infection is the best course of action.

Roundworms are the classic parasite found in faeces, and definitely a good reason for dogs to avoid other dog’s poo. Most common in puppies, particularly those found in dirty environments like puppy farms, they cause diarrhoea, bloated stomachs and weight loss. High burdens can even cause the puppies to waste away. They are primarily spread in the uterus and in milk to puppies, or to adult dogs by ingesting the eggs in faeces. So keeping the environment clean is crucial, whether it is within a litter box or outside in the park.

Humans and Parasites

This is where it gets really disgusting. Many of the same parasites that infect dogs can also infect humans as well. And to make matters worse, they can cause more problems than just diarrhoea.

Both crypto and Giardia, as well as some roundworms, are zoonotic (transmissible from animals to humans). This means we can become sick with them if we ingest any dog faeces accidentally. Luckily, the risk of infection from both of these is low, but still a possibility. If your dog is diagnosed with any of these parasites, you should take extra precautions when you clean up after them, both for yourself, and for other dogs and people.

One roundworm in particular, Toxocara (as well as related genera of roundworm) has an even nastier way of infecting humans. If the eggs hatch in poo before being eaten, the little larvae can still get inside us. Sometimes, once in the body, the larvae burrow into the eyes or even the brain, resulting in blindness and neurological signs (ocular/neurological larval migrans). Children, once again, are especially vulnerable. Luckily, it is more common in tropical countries, where the weather favours the larvae, but can still occur in the UK. Children have gone blind as a result of contact with infected dog poo. 

Livestock Parasites

Here’s a bonus reason why dog poo is a problem. Unless you’re a farmer, you might not think this one directly affects you, but if you like eating beef or lamb, or milk, cheese, yoghurt or any other dairy products, it does!

Certain parasites found in dog poo can be transmitted to sheep and cattle, causing disease. 

One group are tapeworms, of which two in particular can be transmitted from dogs to sheep. Taenia ovis and Taenia hydatigena eggs can be consumed by sheep if their fields are contaminated with dog poo. The eggs hatch and grow to adults. The worms rarely cause disease in sheep, and mainly in younger lambs. However, the biggest issue for farmers is the cysts that developing worms form – at the abattoir, the meat is inspected for these cysts. If present, part or even all of the carcass may be rejected for human consumption, meaning the animal is wasted and the farmer loses out on profit needed to run his farm. The simple act of leaving dog mess in a farmer’s field could result in him not making any money that year on his lambs.

It gets even more serious for cattle farmers with Neospora. This protozoan parasite can cause neurological signs and wobbliness in young puppies, but rarely causes disease in dogs. However, if a pregnant cow ingests left-behind dog poo on the field, she can become infected with Neospora. This results in abortion, meaning the farmer loses a valuable calf and potentially even milk from the mother if she stops making any.

To make matters worse, the aborted foetus and placenta are infected with the parasite as well, and other cows can be infected if they come into contact with them. In extreme cases, this can cause ‘abortion storms’ where many cows abort in a short period, potentially ruining a dairy farm. Even if the calf is not aborted, it may be born infected, and be able to pass Neospora onto her offspring the next year. A single dog poo in a field can wreak havoc in a cattle herd – follow warning signs and avoid walking dogs near cow fields.

What to do as a Dog Owner

We hope now that you can see why it is so wrong, and potentially dangerous, to leave dog faeces on the floor, for other dogs, for humans and even for farmers and their animals. Of course, we know that all of our readers are good upstanding citizens and would never leave dog mess behind – but there are still steps you can take to minimise the risk your dog’s poo holds.

1) Clean it up! 

This point should be hammered home pretty well by now, but cleaning up dog poo reduces the risk of infection dramatically. Never leave home without poo bags, and please place the poo in a suitable bin – leaving it lying around means it is easy for the bags to be split and the infected poo inside released into the environment. If this isn’t enough to convince you, remember that you can now be fined for walking your dog without poo bags, with even greater fines for leaving dog poo on the floor.

2) Regularly worm your dog with an effective wormer. 

No drug is 100% effective, but worming your dog regularly (generally every 1-3 months) will reduce their shedding of parasites like roundworms, tapeworms, crypto and Giardia. Regular worming keeps them worm free, prevents reinfection and protects other animals and people. Some over-the-counter products aren’t effective against all worms, so we always recommend a product from your local vets.

3) Ensure your dog’s vaccines are up to date. 

As well as preventing a number of other nasty diseases, regular vaccination (generally yearly) will prevent the spread of parvovirus to young puppies. We also recommend ensuring your puppy stays away from other dogs and places they frequent until 2 weeks after their second primary vaccine.

4) Be wary of raw food diets. 

Remember that raw food diets carry greater risks of infecting other dogs and people, and the evidence behind their effectiveness is limited (see some of our earlier blogs). Never feed a dog raw food if you have young children about. If you are wanting to feed your dog raw food, please ask your vet for advice.

5) If your dog has vomiting or diarrhoea, take extra precautions. 

This means wearing gloves when handling their faeces, cleaning after them with disinfectant regularly, ensuring children, pregnant women, and other at-risk groups avoid your dog, and seeking veterinary advice for treatment. Sick dogs shed bacteria, viruses and parasites in greater numbers.

6) Avoid walking your dog in certain areas. 

This means avoiding play areas and other places where children like to play, farmer’s fields and near medical facilities – the last thing the NHS needs is an MRSA outbreak because you left a dirty gift outside the hospital entrance! Some campaigners are creating special routes for dogs well away from risky areas, with lots of dog bins along the way – they’ve proven to be effective at reducing fouling.

7) General cleanliness. 

This means washing your hands regularly, particularly before eating, washing your dog regularly, and keeping their environment clean. Although housetrained dogs might not be leaving obvious piles of poo on the floor, they can still spread disease from their back end. Regularly cleaning up after them will minimise the risk of infection. You should also avoid letting your dog lick your (or your childrens’) faces, as we all know what happens when dogs lick their bottoms… Please be extra cautious with children, and explain to them why dog poo is nasty and shouldn’t be touched.

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