How Harmful Are Dogs to Humans? — Do Canines Pose a Real Risk to Life

Dogs have earned the title of ‘man’s best friend’ for thousands of years due to their unwavering loyalty and companionship. However, alongside all the positives they bring to our lives, they also bring some potential health risks that need to be considered. 

So, how harmful are dogs to humans? From allergies to zoonotic diseases as well as physical injuries — you may be surprised. 

Zoonotic Diseases From Dogs

Illnesses that can be passed from animals to humans are called zoonotic diseases. In terms of canines, these include:

• Rabies.
• Leptospirosis.
• Ringworm.
• Salmonella.
• Campylobacteriosis.
• Giardiasis.
• Norovirus.

To learn more, check out our guide on What Diseases Can Humans Get From Dogs?

How To Protect Yourself From Zoonotic Diseases?

Here are a few things you can do to prevent cross-contamination and keep both you and your best friend safe and well.

• Ensure you wash your hands after touching your dog or any other animal — especially before you prepare any food.
• Wash your hands straight away after your dog has licked you.
• Never forget to wash your hands after picking up dog poop — even if you use a plastic bag to scoop it.
• Make sure that your children also follow the same rules.
• Be more vigilant if you have vulnerable people living with you, such as very young children, seniors, or pregnant women.

6 Diseases Dogs Can Pass To Humans

While dogs offer us loyalty, companionship, and lots of love, they also have the potential to pose risks to our health. Here are six diseases that can be passed from dog to human, along with their symptoms, how you can catch them, and how you can lower your risks.

1. Rabies

Rabies is a virus transmitted through the saliva of an animal that is infected, such as dogs, bats, and raccoons. Humans contract the disease through either being bitten or scratched by an animal with the virus. 

Symptoms of Rabies in Humans

• Fever. 
• Headache.
• Flu-like symptoms.
• Agitation. 
• Confusion. 
• Hallucinations.

How long it takes for signs to appear depends on how fast the virus reaches the brain, but it won’t be instant — you’re talking one to three months. And, there is no cure for rabies, it’s fatal. 

Rabies Symptoms in Dogs

• Weakness. 
• Paralysis. 
• Seizures. 
• Excessive salivation.
• Aggressive behavior.

Prevention 

• Avoid contact with stray or wild animals.
• If bitten by a potentially rabid dog, seek immediate medical attention for a series of rabies vaccinations. This will prevent the disease from traveling to your brain and taking hold.
• For your dog — you must keep up-to-date with rabies vaccinations.

2. Leptospirosis

Leptospirosis (also known as Weil’s disease) is a bacterial infection in dogs caused by Leptospira bacteria. Found in soil and water, yet it’s usually spread through the urine of an animal carrying the bacteria. Signs of this dog infection generally manifest a couple of weeks after exposure. 

Symptoms of Leptospirosis in Humans

Symptoms can vary widely, ranging from mild flu-like symptoms of aching muscles, fever, and coughing to severe conditions such as jaundice, kidney failure, and meningitis. 

Leptospirosis Symptoms in Dogs

• Fever.
• Muscle pain and stiffness.
• Loss of appetite.
• Vomiting.
• Jaundice.
• Lethargy.

Prevention

• Vaccination against leptospirosis is available for dogs. 
• Practice good hygiene, wash your hands if you’ve been in contact with doggy pee, or wear gloves to avoid it altogether. 
• Use antibacterial cleaning liquid or bleach when cleaning up after an infected dog.

3. Ringworm

Despite the name, ringworm isn’t caused by a worm but rather by a range of fungal species, including Microsporum canis in dogs. 

Symptoms of Ringworm in Humans

Signs of this dog skin condition that’s contagious to humans include red, ring-shaped, scaly patches on the skin that may itch or blister.

The fungus spreads by leaving spores, which you can pick up from contaminated items like the sofa, bedding, or grooming tools. You can also catch it from touching a dog with the infection. 

Ringworm Symptoms in Dogs

• Circular skin lesions.
• Affected skin is often red and inflamed.
• Hair loss.
• Itching.
• Brittle nails.

Prevention

• Regular hand washing after handling animals, especially if they have skin lesions. 
• Keep your dog’s living space clean and dry, and don’t share things like grooming tools or bedding between pets. 
• Any suspected cases of ringworm should be treated swiftly to prevent the spread to other animals or humans.

4. Salmonella

Salmonellosis is an infection caused by Salmonella bacteria. These germs live in the digestive system and are excreted in the poop of infected animals, including dogs. Canines catch it in the same way humans do, via eating contaminated food, for example, raw meat or unrefrigerated wet food.

Symptoms of Salmonella in Humans

• Diarrhea. 
• Abdominal cramps.
• Fever. 
• Vomiting. 

Transmission to humans can occur through infected feces and urine.

Salmonella Symptoms in Dogs 

• Diarrhea.
• Vomiting.
• Fever.
• Loss of appetite.
• Lethargy.

Note: Some dogs are simply carriers of the germ and show no signs at all. 

Prevention

• Wash your hands thoroughly after handling pet food or cleaning up after your dog.
• Discourage your dog from scavenging or eating raw meat.

5. Campylobacteriosis

Campylobacteriosis is a bacterial infection caused by Campylobacter bacteria in the feces of animals carrying the germ. 

Symptoms of Campylobacteriosis in Humans

• Diarrhea (often bloody) lasting for around one week. 
• Abdominal pain. 
• Fever. 
• Nausea. 

It can be passed to humans through contact with infected animals or their poop.

Campylobacteriosis Symptoms in Dogs

• Diarrhea
• Vomiting
• Fever. 

You may also notice a change in your dog’s appetite and subsequent weight loss. Puppies under 6 months are most at risk of this illness. Yet some dogs are merely hosts for the bacteria.

Prevention

• Wash your hands thoroughly with soap and water after handling pets, especially those with diarrhea. 
• Prevent contact with pet feces and disinfect contaminated surfaces regularly.

6. Giardiasis

Giardiasis is a parasitic infection caused by the protozoan parasite Giardia duodenalis, which can be found in the poop of infected animals. 

Symptoms of Giardiasis in Humans

• Diarrhea. 
• Abdominal cramps. 
• Bloating. 
• Weight loss.

Giardia in dogs to humans is usually transmitted through contact with contaminated animals or their feces.

Giardiasis Symptoms in Dogs

• Diarrhea. 
• Weight loss.
• Vomiting. 
• Gas. 
• Abdominal pain.
• Lethargy.

Prevention

• Good hygiene, frequent handwashing with soap and water, particularly after handling animals and poop. 
• Ensure that pets have access to clean drinking water and prevent them from drinking from potentially contaminated water sources. 
• Clean up and dispose of pet poop quickly to minimize environmental contamination.

How Else Can Humans Get Sick From Dogs?

Dog Allergies and Asthma

For around 10 to 20% of the population, exposure to dogs can trigger allergies and make asthma symptoms worse. Dog dander, saliva, and urine contain allergens that can cause allergic reactions. The allergy to dog symptoms can range from mild to extreme but usually include the following:

• Sneezing.
• Itching.
• Runny eyes.
• Skin irritation.
• Runny nose.

Considering how popular dogs are, with 33% of the global population owning one, they can pose a significant risk to the health of those allergic to dogs. 

Prevention

While you can’t prevent allergies, you can reduce the risk of triggering a reaction by:

• Using an air purifier for dog hair. 
• Grooming your dog regularly to remove dead hair.
• Choosing a low-shedding/hypoallergenic dog breed. 

For more information, take a look at our guide on How To Get Rid of Allergies Naturally.

Physical Injuries From Dogs

One of the most visible examples of how dogs are harmful to humans is the potential for physical injury from being bitten. 

Dog bite symptoms in humans can range from puncture wounds, lacerations, and in severe cases, life-threatening injuries if medical assistance isn’t sought. What’s more, thanks to bacteria in your dog’s mouth, a bite wound can become infected, which could develop into cellulitis. 

Prevention

• Those most at risk from domesticated dog bites are children, mainly due to their small stature and limited understanding of dog behavior. However, this can be significantly reduced if children are taught how to behave around dogs and know the warning signs to look out for.
• For dogs, correct training and plenty of socialization can help reduce the risk of aggressive behavior toward people — lowering the rate of dog bites.

Treatment

• If the wound is bleeding, apply pressure to stem blood flow — if bleeding hasn’t stopped after 10 minutes, seek medical attention. 
• Clean the affected area — remember that a dog bite, even a minor one can introduce bacteria into the bite, which can lead to infection. So, make sure that it’s thoroughly washed with clean, soapy water.
• Apply an antiseptic such as iodine to the area. This will help to disinfect the area again and reduce the risk of infection. Then, keep it covered with a bandage. 

Psychological Impact of Dogs on Humans

Cynophobia 

For those with an extreme fear of dogs, being close to a canine can trigger intense distress. This phobia may stem from a perceived threat of aggression or unpredictability, which can then lead to avoidance of certain areas, situations, or even family that goes on to compromise their quality of life.

Trauma From Dog Attacks

Dog attacks can have a serious psychological impact on both victims and witnesses. Survivors can experience intense fear, anxiety, and post-traumatic stress disorder (PTSD), which in turn, can lead to nightmares, flashbacks, and hypervigilance. 

Witnessing a dog attack can also leave mental scars, particularly for children, who can develop a fear and distrust of dogs.

Noise Pollution From Dogs

Barking, whining, and howling are all common noises that dogs make, but in residential areas, they can contribute to noise pollution, causing stress to your neighbors. 

Continual barking can disrupt sleep patterns, increase irritability, and make existing mental health conditions worse. Ensuring responsible pet ownership practices such as training as well as providing a rich environment for your dog all help with this issue. 

The Benefits of Dog Ownership to Human Health

While we’ve looked at diseases transmitted by dogs to humans and everything else in between, owning a dog has also been linked to a number of health benefits. Regular interaction with dogs can:

• Promote physical activity.
• Lower blood pressure. 
• Reduce the risk of cardiovascular diseases. 

Positive Effects on Mental Health

One bonus is the companionship dogs provide. Being in the company of a dog has been shown to have positive effects on the state of psychological well-being, including:

• Reduction in stress.
• Lowering anxiety.
• Improving symptoms of depression. 

Interacting with a dog can trigger the release of oxytocin and endorphins — hormones associated with happiness and bonding — making people feel calm and emotionally stable. 

For example, therapy dogs, in particular, play a vital role in providing comfort and support to individuals facing various challenges, including those with mental health disorders. 

In short, dogs have the potential to make you smile, and for many, this seemingly tiny thing can make all the difference. 

Conclusion

It’s a fact — dogs can make you sick from disease, cause physical injury, and impact your mental health. Yet, on the flip side, they can also keep you fit and boost your state of mind. 

Being aware of how harmful dogs are to humans and how you can prevent these things from happening are all part of responsible doggy ownership. And, don’t forget, there are plenty of pluses that go hand-in-hand with canine companionship, including unconditional love. 

Dog Diseases to Humans FAQs

What Diseases Can Humans Get From Dogs?

Dogs can pass on both bacterial and viral infections to humans, such as:

• Rabies.
• Pasteurella.
• Salmonella (salmonellosis).
• Yersinia enterocolitica (yersiniosis).

Can Humans Get Bacterial Infections From Dogs?

Yes. Bacterial diseases transmitted by dogs to humans include:

• Campylobacteriosis.
• Salmonellosis.
• Leptospirosis. 
• Brucellosis.

What Diseases Can You Get From Dog Saliva?

Capnocytophaga canimorsus is one of the dog diseases transmitted to humans through saliva. This bacteria causes infection that can lead to severe sepsis, which can be potentially fatal.

Can Dog Fungus Transfer to Humans?

Some fungal diseases like ringworm can be spread from dogs to humans. However, fungal dermatitis in dogs isn’t contagious.

Can Humans Get Giardia From Dogs?

Humans can catch giardia from dogs, but the odds are relatively low. This is because there are seven different parasites — A to G. However, types A and B can be contracted by both dogs and humans.

Can Dogs Get Sick From Humans?

There are a few illnesses that you could potentially pass on to your pup, and these include:

• Influenza virus.
• SARS-CoV-2.
• Mumps.
• Salmonellosis. 
• Ringworm.

However, experts suggest that the human/dog transmission rate is pretty low.