Zoonotic Diseases

(Pets can give people so many things: love, attention, entertainment, company; as well as, infection)

Being aware of some of disease problems from pets can help to keep both people and pets healthy

Whether people own a dog or a cat, a bird or a reptile, a rabbit or fish; they all should be aware that a pet can have an effect on their health by infecting them with certain diseases. These are called zoonotic diseases, which are animal diseases that can be transmitted to humans.

Some people may already know about some of the more common zoonotic diseases passed on by animals: Lyme disease is a bacterial disease transmitted by tick bites; malaria is transmitted by the Anopheles mosquito, and bubonic plague is transmitted by rats, or rather by fleas that become infected by biting the rats; however, everyone should also be aware of several common zoonotic diseases that can be transmitted by their pets:

  • Hookworms and Roundworms: a disease caused by gastrointestinal parasites.
  • Infection can occur from either ingesting parasite eggs or coming into contact with the larva in the soil. These parasites can be acquired from handling infected soil through gardening, cleaning feces, walking in sand, or playing in sandboxes used by animals. Children are most often affected.

  • Psittacosis: a bacterial disease anyone can get by inhaling dust from dried bird droppings.
  • Rabies: a viral infection caused by a virus found in the saliva of infected animals and is transmitted to pets and humans by bites.
  • Infected bats, raccoons, foxes, skunks, dogs or cats provide the greatest risk to humans.

  • Leptospirosis: a bacterial disease you can acquire from handling infected urine or by putting your hands to your mouth after touching anything that has come into contact with infected dog urine.
  • Ringworm: a contagious fungal infection that can affect the scalp, the body (particularly the groin), the feet and the nails. Despite its name, it has nothing to do with worms.
  • The name comes from the characteristic red ring that can appear on an infected person's skin.

    All animals can acquire zoonotic diseases, but animals at increased risk include: outdoor pets, unvaccinated animals pets, that are immunocompromised (a suppressed immune system), poorly groomed animals and animals that are housed in unsanitary conditions. People with immune disorders, on chemotherapy or immunosuppressive therapy may be at increased risk of infection.

    Animals with zoonotic diseases may exhibit a variety of clinical signs depending on the type of disease. The signs can vary from mild to severe. As a pet owner everyone should know his/her animal and be aware of any changes in behavior and appearance.

What to Watch for




Skin lesions/rashes




Weight loss


Bruising under the skin

Joint swellings


People need to know more about zoonotic diseases

There are large numbers of zoonotic diseases that can potentially affect people which are caused by a wide variety of bacteria, parasites, viruses, and fungal organisms. People may become infected by a number of different routes.

Poor sanitary habits may lead to the ingestion of small amounts of animal waste products and transmission of zoonotic disease. Fecal waste is a source of many bacterial and parasitic infections, and even urine contamination can lead to disease; for example, Leptospirosis. Ingestion of undercooked food products, skin contact with infectious agents (e.g. ringworm, fleas, mites), and bite wound or scratches are all potential modes of zoonotic transmission.

Many zoonotic diseases are not directly transmitted from animals to people, but they require an intermediate host (a vector); such as, a flea or a tick, for transmission to occur. The dog or cat brings the vector into the household where humans can become exposed.

Some individuals are at greater risks than others

Even though many zoonotic diseases include some very common aliments in animals, serious disease in people is relatively uncommon. Certain individuals, however, are at increased risk.

  • Young children are probably at highest risk because they are more likely to be exposed to animal excrements during play.
  • Additionally, wild animals or cats may defecate in sand boxes where children play. Poor hygiene habits practiced by children also make them naturally at increased risk for many zoonotic diseases.
  • People with suppressed immune function because of chemotherapy, organ transplants, or immunosuppressive drugs are also at increased risk.
  • Individuals with acquired immunodeficiency syndrome (AIDS) are also more susceptible.
  • In addition, some zoonotic diseases (e.g. toxoplasmosis) that cause only mild or self-limiting disease in healthy people may be life threatening in immunocompromised individuals.
  • Finally, certain culinary practices may lead to an increased risk of contracting a zoonotic disease.
  • Eating raw or undercooked beef is a common cause of transmission of toxoplasmosis.
  • Eating undercooked eggs may lead to salmonellosis.
  • Hikers that drink unfiltered or untreated water have a greater risk of acquiring giardia.

Everyone needs to be aware of zoonotic diseases

A good knowledge of the most common zoonotic diseases and routine health care with good husbandry and sanitation practices will significantly decrease the likelihood of either the person or the pet acquiring a zoonotic disease.

A veterinarian routinely provides yearly exams, preventative internal and external parasite control programs and vaccinations. These services dramatically reduce the zoonotic potential of disease.

Additionally, veterinarians usually provide information and consultation on training and behavioral issues. This advice is extremely important, since the most common zoonotic diseases caused by small animals are bite and scratch wounds.

Veterinary Care

A veterinarian will need a good history, including an accurate travel history and complete physical examination in order to make an accurate diagnosis. Since there are so many different kinds of zoonotic diseases, the veterinarian will also do various diagnostic tests. Some of these may include blood tests, cultures, x-rays, or ultrasounds.

Treatment depends on the specific diagnosis and may include antibiotics, anti-parasitic drugs, or anti-fungal drugs; intravenous fluids; symptomatic care for associated conditions (e.g. vomiting or diarrhea); and analgesic (pain) medication.

Preventative Care

Not all animals with zoonotic diseases are serious risks to people, but good hygiene practices should always be observed. Proper education, a good understanding of the disease and its method of transmission are a vital part of home and preventative care.

Use proper hygiene and sanitation when handling pets and their excretions and maintain a good program of veterinary care.