Pet Pests That Harm Humans

Fleas, Ticks, Worms and Mosquitoes…These common pests are the ones pet owners are most familiar with. In fact, you probably have your companion on a parasite preventative that protects them from these pet foes. (If not, please call us to set your pet up with the right defense!)

But did you know that these and other parasites that are troublesome for the animal kingdom can also bring harm to human family members? That’s right. So while you are protecting your pet against parasites, you are, in turn, protecting your family from illnesses resulting from parasites.

Let’s take a look at why pet parasite protection promotes the health and wellbeing of ALL family members.

Parasites in Our Midst

A good hike through the woods is great exercise, but your pooch likely encounters plenty of bugs along the way. How about an afternoon at the local dog park, where other pets congregate? Even if your pet lives indoors except for daily walks, there are still plenty of chances to encounter pests and parasites.

Here are some reasons why these pests should not be present in your home (or on your pet).


One of the most invasive pests your pet can carry is the common flea. In less than month, one flea can turn into 1,000 fleas. While they often start with your pet as the host, they will gladly jump to any warm-blooded mammal, and that includes you.

What is the danger? Aside from uncomfortable scratching, fleas are the carriers of diseases and parasites, such as:

  • Intestinal worms like tapeworm 

  • Bartonella (also known as Cat Scratch Disease)

  • Tularemia

  • Typhus 

  • Plague 


Ticks are the second most common pest found on pets, especially on dogs. Ticks are most active in the spring through autumn, but they are a year-round issue and one of the biggest threats to humans as far as parasites go.

Lyme disease affects 30,000 people each year, and carries lifelong neurological (among other) problems. Other diseases that can be transferred from animals to people via ticks include Rocky Mountain spotted fever, anaplasmosis, tularemia, and babesia.


We are all too familiar with these blood-sucking pests, but are we as familiar with the problems they carry? For our furry friends, mosquitoes carry a deadly parasite, heartworm. It can take 5-6 months for heartworm larvae to travel to the heart chambers and begin damaging the heart, which is why a monthly preventative is so important!

There are several diseases carried by mosquitoes, such as malaria, dengue, yellow fever, and chikungunya (though most are not common in our area). While heartworms are not a threat to humans, they can do irreversible damage to your pet.


Cases of leptospirosis are steadily increasing in the United States. This disease is spread through contact with water or soil contaminated by the urine of infected animals, which can include your pet. This bacterial disease can cause high fever, headache, bleeding, muscle pain, and vomiting, and can be fatal to both pets and people.


The most common intestinal parasite are worms, especially Roundworms. If you accidentally ingest roundworm eggs transmitted by an infected pet, these can hatch in your own intestines and travel to other parts of your body. 

Misconceptions About Pet Parasites 

Parasite prevention is not just an animal issue, as there are many vector-borne diseases that can be transferred to people. By treating your pet accordingly, you can safeguard the entire family.

Another misconception is that parasite prevention is only a spring and summer issue.  Contrary to popular belief, fleas, mosquitoes, and ticks (and especially worms) can be a year-round problem, so be sure to invest in good preventatives. 

There are many different types of preventatives and every pet is different. Please talk to one of us here at Union Lake Veterinary Hospital if you have any questions or concerns.