Guide to zoonotic diseases

Zoonotic diseases are a specific category of contagious illnesses that you can catch from animals. Many zoonotic diseases are quite concerning, and some can even be fatal. One of the most common ways to contract one of these illnesses is when an animal enters your home to make a nest, escape the elements, or search for food. At Critter Ridder, we strive to make sure that you won’t cross paths with a pest carrying one of the following zoonotic diseases.


Rabies is a preventable zoonotic illness that is most frequently transmitted through the bite of an infected small mammal, such as a raccoon, skunk, or opossum. Domestic animals can also be infected with the rabies virus, which is rapidly fatal if left untreated.

The disease impacts the central nervous system and the brain. The Centers for Disease Control (CDC) advise that early warning signs include headache, fever, weakness, and general aches and pains. These symptoms can mimic many other illnesses, making rabies hard to detect.

Raccoon Roundworm

Raccoon roundworm, or Baylisascaris procyonis, is labeled by the National Institutes of Health (NIH) as a helminthic zoonotic disease, meaning that it is carried by parasitic worms. Raccoons carry the roundworms and then deposit them in their waste. This is the most common way that humans contract the roundworm, with the majority of reported patients being children who come in contact with the worm while playing on the ground outside.


The Journal of the American Osteopathic Association (JAOA) calls giardiasis an “under-appreciated” zoonotic disease. Recent statistics indicate that infection is increasing as people live in ever closer proximity to infected animals.

Giardiasis is caused by a strain of the parasite giardia, and can be carried by species including rats, beavers, muskrats, deer, and coyotes. Animal waste is the most frequent cause of transmission from an infected animal to a person. In most cases the illness will cause diarrhea and will run its course without lasting damage. However, in children the disease can be more severe and may cause developmental delays without prompt treatment.


Hantavirus is transmitted from infected rodents to people. It can be deposited in saliva or waste of infected animals. As MedlinePlus reports, hantavirus can cause a dangerous secondary infection called hantavirus pulmonary syndrome, or HPS.

Some recent fatal cases among adults and children have brought hantavirus to the forefront of community attention once again. An estimated one-third of patients who contract the disease will die.


Histoplasmosis is a zoonotic fungal disease that affects the lungs and can cause chronic breathing issues. This disease is most frequently contracted by coming into contact with waste from bats and birds. Symptoms can vary from short-term and acute to chronic and ongoing. Children and the elderly are most at risk for serious and repeat infections.


Leptospirosis is an emerging zoonotic disease of worldwide concern, according to the NIH. Large-scale outbreaks have been reported in recent years, often due to natural disasters such as flooding, which bring people in contact with animal waste from species including rats, raccoons, skunks, opossums, and squirrels.

The bacteria can cause symptoms ranging from mild to severe. An estimated 10 percent of patients develop a more serious form that targets the vital organs. This form is chronic and can require hospitalization. Even with treatment, severe leptospirosis can result in death.

Keep Yourself Protected

If you fear you may have a critter problem on your hands, don’t worry – Critter Ridder is here to help! We’ll identify your problem, remove the critters in question and put prevention measures in place to keep them from returning. Contact us today and make sure your family and home are safe.