Zoonotic diseases are infectious diseases that affect animals and can be transmitted to humans.
Many zoonotic diseases are spread through direct or indirect contact with affected animals. Some are transmitted via vectors like fleas, ticks, and mosquitoes. Others can be foodborne.
01 of 10
Cat Scratch Disease
Commonly called "Cat Scratch Fever," this disease is caused by bacteria called Bartonella henselae. Cats typically contract the bacteria from blood-sucking external parasites like fleas, ticks, lice, and biting flies. Bartonella henselae does not generally cause illness in cats.
Humans can contract cat scratch disease after getting a cat bite or scratch that breaks the skin. They can also get it if an infected cat licks an open wound on the human. Dogs can get the disease in the same ways.
Bartonella henselae often causes swelling at the injury site along with enlarged lymph nodes near the injury site. Other signs of infection include fever, lethargy, loss of appetite, and headache. People and dogs can be treated with antibiotics if necessary. In rare cases, cat scratch disease can become very serious, affecting the eyes and other major organs. Fortunately, most people and dogs are able to make a full recovery.
02 of 10
Giardiasis is a disease caused by Giardia, a group of microscopic single-celled parasites that can infect a number of animals, including dogs, cats, rodents, and humans. The protective cysts of these organisms allow them to survive in harsh environments until they can infect a new host.
Infection occurs when the Giardia parasite is ingested, causing severe diarrhea and sometimes vomiting. Animals may walk through contaminated soil and lick it off the paws, drink contaminated water, or contract Giardia from another infected animal. Although it is possible for humans to get giardiasis from an infected animal, it is relatively uncommon. Humans most often get giardiasis from drinking contaminated water.
Animals being treated for giardiasis should be bathed regularly and taken to an isolated area to defecate. The giardia cysts are shed in the stool and can remain on the animal's body. People coming into contact with infected animals should thoroughly wash their hands after.
Fortunately, giardiasis can be treated with medications like antiparasitics and antibiotics. Patients often need supportive and symptomatic care such as anti-diarrheal medications and fluids to maintain hydration.
03 of 10
The hookworm is a common intestinal parasite in dogs and cats that causes diarrhea, loss of appetite, and anemia. Dogs and cats can get hookworms from their mothers (in the womb or when nursing) or from ingesting contaminated soil. This includes ingestion during routine grooming.
The hookworm can also penetrate the skin of dogs, cats, and humans and cause a localized reaction that is swollen and itchy. Humans can also get the intestinal parasite if they accidentally ingest the larvae, but this is far less common.
Prevent accidental ingestion by wearing gloves while handling soil or coming into contact with infected animals, then by washing your hands well. Wash fruits and vegetables before consuming. To prevent hookworms from penetrating your skin, avoid walking barefoot in areas where animals may have defecated. Make sure you screen your pets annually (or more) for hookworms and other parasites.
Fortunately, hookworm infections can be treated with antiparasitic drugs. Most affected animals and humans will make a full recovery.
04 of 10
Leptospirosis is a bacterial disease caused by bacteria of the genus Leptospira. The bacteria are often carried in the urine of by rodents and other wildlife. Animals and humans coming into contact with contaminated water, mud, and soil can contract the disease. They can also get it via direct contact with the urine of an infected animal.
Dogs, livestock, and humans are all susceptible to leptospirosis. Illness is rare in cats, but they can still carry and transmit the bacteria. While some animals and humans will fight off the bacteria and never become sick, others can get very ill. Leptospirosis often begins with flu-like symptoms. If it progresses, it can affect the major organs, especially the liver.
Treatment involves antibiotics and supportive care. Prevent exposure by getting your dog vaccinated against leptospirosis. Avoid coming into contact with the urine of affected animals.Continue to 5 of 10 below.
05 of 10
Rabies is a serious viral disease that affects mammals. The virus adversely affects the central nervous system, leading to death. Rabies is one of the most dangerous zoonotic diseases known.
Rabies is usually transmitted via saliva, most commonly after a bite from an affected animal. Any mammal can contract rabies, including dogs, cats, and humans.
Rabies often starts with flu-like symptoms that progress to neurological dysfunction. It can lead to behavior changes, disorientation, seizures, and aggression. There is no cure for rabies and no treatment available for non-human animals.
Humans exposed to rabies can be treated with a series of post-exposure vaccinations and human rabies immune globulin. However, it cannot be cured once symptoms develop.
If you are bitten by an animal, it is essential that you see your doctor right away, especially if the animal has not been vaccinated. All dogs and cats should be regularly vaccinated against rabies to prevent the spread of this fatal disease.
06 of 10
Despite its name, ringworm is neither a worm not a parasite. It is named such due to the worm-like appearance of lesions on the skin. Also called dermatophytosis, ringworm is a fungal infection of the skin that can affect most animals, including dogs, cats, rabbits, rodents, and humans.
Ringworm is contracted by direct contact with an affected animal or person. The fungus causes red, scaly, circular lesions on the skin that itch. It causes hair loss in areas where hair normally grows.
Ringworm is fairly easy to treat with antifungal medications and topical applications. Fortunately, this is not generally a serious condition. However, it can be a nuisance to get rid of once it starts spreading to animals and humans in the household. Young, elderly, and immune-compromised individuals are at the greatest risk.
07 of 10
The roundworm is another common intestinal parasite in dogs and cats, especially puppies and kittens. Roundworms cause diarrhea and can have a serious impact on small, young animals. Dogs and cats usually get roundworms from their mothers in the womb or via nursing. They can also get infected from ingesting contaminated soil.
Humans can also get the intestinal parasite if they accidentally ingest the eggs, which are left in the environment by infected animals. After ingestion, the larvae can migrate through the body, affecting the eyes and internal organs. Fortunately, this is relatively uncommon.
Avoid exposure by wearing gloves while handling soil or coming into contact with infected animals. Always wash your hands well afterward. Be sure you screen your pets annually (or more) for hookworms and other parasites.
Fortunately, roundworm infections can be treated with antiparasitic drugs. Most affected animals and humans will make a full recovery. However, when the roundworms affect a human's eye, the disease can be more serious and may result in permanent eye damage.
08 of 10
Commonly called scabies, sarcoptic mange is a skin condition caused by the Sarcoptes scabiei mite. The mites burrow into the skin and cause a red, itchy rash. In animals, scabies causes patchy hair loss, scaly skin, and intense itching.
Scabies can affect most animals, including people. However, transmission between species depends on the type of Sarcoptes scabiei mite, as some are species-specific.
Humans can get scabies through close contact with affected animals. In addition, humans with scabies can pass the mites to other humans. Treatment involves the use of topical creams or ointments and oral antiparasitic drugs. Animals may also need special baths or dips. It can take several weeks or more for pets and people to fully recover from scabies.Continue to 9 of 10 below.
09 of 10
Ticks carry several diseases, including Rocky Mountain Spotted Fever, Lyme Disease, and Ehrlichiosis. Many tick-borne diseases affect both humans and animals. These diseases are not directly transmitted between humans and animals. Instead, ticks are vectors for the diseases, carrying them between hosts.
The signs of tick-borne diseases can take several months to appear and most affect the immune system. Symptoms vary by disease, but most cause flu-like symptoms at first. Some diseases will cause skin rash and/or joint pain.
Diagnosis and treatment of tick-borne diseases can be complicated. Recovery depends on the specific disease and the patient's individual immune system.
10 of 10
Toxoplasmosis is a disease caused by the protozoan parasite Toxoplasma gondii. This parasite can be transmitted to most animals and humans. However, it is generally only found in cat feces and, less commonly, undercooked meat.
Toxoplasmosis is often asymptomatic in companion animals. Most healthy humans with the parasite are also unaffected. However, toxoplasmosis can cause serious health problems for unborn babies and people with compromised immune systems. It may also cause miscarriage or stillbirth. This is why it is so important for pregnant women to use extreme caution around cat litter boxes and raw foods.
In the rare cases that humans are made ill by toxoplasmosis, the symptoms can be vague. Mild fever, headache, and muscle aches are the most likely initial signs. In serious cases, the parasite can damage the brain. Treatment usually involves antibiotics and supportive care.