Given we’re all hyperaware of disease right now, you might be trying to do everything you can to avoid getting sick. We all know we should wear a mask and wash our hands to avoid catching something from another person. But should you be concerned about catching diseases from your dog? Today we will be answering this question and explaining some of the diseases you might want to consider as a dog owner.
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So Humans Catch Diseases from Animals?
Definitely! A bacterium, virus, fungus, parasite or other disease that can be transmitted from an animal to humans is known as a zoonosis. And there’s plenty of them! In fact, the CDC estimated that over 60% of human diseases are potential zoonoses, and around ¾ of new diseases are zoonoses. The Black Death plague, swine flu and (probably) COVID-19 are all diseases that originated in animals before infecting humans.
Zoonoses can be transmitted from animals in the air (like influenza or COVID-19), or via animal saliva, blood, faeces, urine or other fluids. Being bitten is a common way blood-borne infections are transmitted. Some zoonoses are transmitted from animals to humans via vectors, such as insects like mosquitoes or sandflies. Regardless of the method of transmission, the more we come into contact with animals, the more likely it is that diseases will spread to humans. (This is one of the reasons why human encroachment into the environment makes diseases like COVID-19 more likely to emerge).
There are also some rarer cases of reverse-zoonoses, or anthroponoses, where humans transmit a disease to animals. There aren’t too many we need to worry about as pet owners (zoonoses are more important to think about). Although MRSA in dogs is one fairly common example.
What Diseases Can I Catch From My Dog Then?
There’s quite a few, far too many for us to discuss in this short article, but we will go over some of the most common now.
Probably the most common group of zoonoses to think about in dogs are parasites. Parasites are either internal worms or external parasites like fleas, mites and lice.
Starting with worms: most worms are transmitted to your dog when they eat the parasites’ eggs, usually picked up from the environment or animal faeces. Preventing your dog eating faeces, food on the floor, or soil can help prevent parasitic infection. Regular de-worming with drugs prescribed from your vet is the most important way to prevent infection, particularly in young dogs that are most susceptible to worms.
Most worms cause mild gastrointestinal signs in dogs and people. However, there are a number of nastier ones that can migrate to the muscles, eyes and brain, causing terrible neurological disease. Children and pregnant women are especially vulnerable, so ensure they do not handle dog faeces. You should also avoid letting your dog lick your face, as this could transmit the eggs into your mouth.
External parasites, on the other hand, tend to cause skin rashes, itchiness and infection. However, some external parasites also carry other diseases that are transmitted when they bite us, such as zika, malaria and tick-borne fever. Thankfully, most are rare in this country, but it is still worth being careful. Again, preventing them infesting your dog involves keeping the environment clean and regular anti-parasite treatments.
Rabies is a well-known zoonotic disease that is transmitted in saliva, commonly from being bitten by a rabid animal. Wildlife, as well as dogs, can carry rabies. This nasty virus replicates in the brain of creatures it infects, and causes aggression, salivation, pain, fear of water and eventually death. If you are ever bitten by a wild animal, contact a doctor immediately. Nowadays, prompt treatment will prevent the worst symptoms.
Thankfully, rabies is not currently present in the UK, so no dog should be infected with rabies. However, it is widespread in much of the rest of the world. This is why there are strict rabies control measures when you travel to and from the UK to prevent it being imported back to the country – a canine rabies vaccine is mandatory for dogs travelling abroad if they want to avoid a long stay in quarantine. Without, your globetrotting dog could be vulnerable if bitten by a rabid dog or wildlife, and potentially pass the disease on to you.
Regardless if you travel with your dog or not, avoid any aggressive or hypersalivating dog, and contact your doctor or vet urgently if you or your dog are bitten by one. Border controls are never 100% effective, and it may only be a matter of time before rabies rears its ugly head in the UK again…
Confusingly, ringworm is not a worm. Ringworm is a fungus that colonises living skin and hair, causing itchiness, hair loss, crusting and secondary skin infections. It often forms ‘bullseye’ patterns on the skin giving it its name (though not always). It is more common in young dogs, especially those in large groups in unclean environments.
The disease is generally not dangerous, but can cause a considerable welfare issue. If your dog has ringworm, you must be careful to wear gloves when touching them to avoid catching it yourself. If you end up with itchy skin, see your doctor straight away. Luckily, ringworm can be treated with topical washes or oral anti-fungals, as well as intense environmental hygiene. It can take months to clear up.
Ringworm is also one of those anthroponoses, so if you have ringworm be careful around your pets as they could easily pick it up from you.
Salmonella, Campylobacter, E. coli and other similar bacteria are best known as food poisoning bacteria, causing horrible vomiting and sickness. However, did you know that they are also zoonotic? There are a few ways you can catch these bugs from your dog.
The first is the most common way, via the faecal-oral route. Faeces is, of course, covered in bacteria (as well as the aforementioned parasite eggs), and accidentally ingesting it can result in infection, even if your dog is not sick. This is why you should wash your hands after cleaning up dog mess, and ideally after any contact with your dog if you are about to eat food. Pregnant women, children and the elderly are especially vulnerable to sickness bugs, so should be extra careful. Dogs can be infected with these bacteria in the same way and show similar vomiting and diarrhoea symptoms – be extra careful with the bodily fluids of dogs with vomiting and diarrhoea.
The second form of infection is not exactly zoonotic infection, but important to mention regardless. Raw diets are becoming popular as a feeding method. The jury is still out on whether these kinds of diets are appropriate, but a lot of people find it helps their dogs for individual problems. However, one of the biggest risks with raw feeding is the spread of bacteria around the house. Dogs are not careful eaters, and when eating raw meat can spread the bugs all over. If you choose to raw feed your dog, take extra cleaning precautions, wash your hands more frequently, ensure the meat is from a reputable seller and store it appropriately in a fridge apart from your own food. These should reduce the risk of spreading Salmonella and other bacteria around the house where they could be picked up and make you ill.
You’ve probably heard of leptospirosis, or lepto, when you get your dog’s annual boosters. Leptospirosis is a bacteria that resides in animal urine, standing water and soil. Rats in particular are a common source of infection. We, of course, recommend that all dogs are vaccinated against leptospirosis. But it is especially critical for those that frequently swim in, or drink from, canals, lakes and streams where wildlife urine can run into.
Dogs infected with leptospirosis become feverish, go off their food and often appear quite sick. If untreated, the bacteria can cause severe damage to the kidneys and can even be fatal. Humans infected with leptospirosis can get the same symptoms, as well as brain damage. We are infected in the same way so always be careful where you swim. If your dog is infected with leptospirosis it will be producing the bacteria in its urine, so ensure you do not touch it and take extra precautions. Luckily, vaccinating your dog against multiple strains of leptospirosis will protect them and you very effectively.
So we come to the big one. You may have heard news stories of cats, dogs, ferrets and even zoo animals becoming infected with COVID-19. It appears most of these infections originated from humans, a good example of an anthroponosis. Luckily, the disease is often not dangerous in animals as most just have mild respiratory disease.
Is COVID-19 zoonotic though? Of course, it likely originated from bats or other wildlife, so was originally zoonotic. But there is also a very small risk that domestic animals infected with COVID-19 could pass it back to humans. The risk of this is thought to be incredibly low however.
The government currently recommends washing your hands after contact with your pet (which you should do anyway), and contacting your vet if you suspect your pet may have COVID-19. Some practices can now test for the disease in pets. Owners of ferrets are advised to isolate their ferret for 21 days if a human is infected with COVID-19, due to ferrets in particular being more likely to spread it back to humans. In short, you likely don’t need to take any extra precautions with your pets if you do not have COVID-19. But it is important to be aware that COVID-19 can be passed between humans and their pets on very rare occasions.