Zoonotic Diseases – An Introduction

Not many people are aware but veterinary medicine has a proud history and tradition of promoting and improving the health of not only animals but of humans as well.  Veterinarians receive an education in physiology and clinical science comparable to that of physicians but they also receive extensive training in comparative medicine.  We are educated in preventive medicine, population health, parasitology, zoonotic diseases, and epidemiology and not to mention we must be familiar with a multiple number of species.  Because of this training veterinarians have and continue to make significant contributions to the control of infectious diseases of humans.   

In one way or another all veterinarians regardless of their specialty are involved in protecting humans from diseases, in particular those transmitted between humans and animals.  These diseases are called zoonotic diseases.  According to the CDC approximately 75% of emerging infectious diseases affecting humans are of animal origin and approximately 60% of all human pathogens are zoonotic (http://www.cdc.gov/ncezid/).   I personally don’t like the term emerging disease because many of these diseases aren't necessarily new.  Therefore, the more correct term in my opinion for many of these diseases is re-emerging infectious diseases.  So why are we now seeing what appears to be an increase in infectious diseases?  The difference is that theses diseases now have the potential to cause worldwide epidemics.  The world has become much smaller and much more vulnerable to the spread of infectious diseases.  Another reason is changes in our environment including logging of forests, changes in the use of land, migration of people from rural to urban areas and improper disposal of waste.  Zoonotic diseases affect and kill hundreds of thousands of people especially in developing countries, even though most of them can be prevent.

Examples of zoonotic diseases classified according to their infectious agent include:

·      Parasites: Toxoplasmosis, Cysticercosis

·      Bacteria: Anthrax, Leptospirosis, Tularaemia

·      Fungi: Dermatophytoses, sporotrichosis

·      Viruses: Rabies, Hantvirus

·      Prion: Bovine Spongiform Encephalopathy

Please don’t let this information scare you.  Throughout this blog we will cover various zoonotic diseases and ways to protect yourself, your family and pets from them.  And please remember pets provide many health benefits to humans; examples include decrease blood pressure, cholesterol levels, and triglyceride levels.  They also can provide a great source of exercise.   Although pets can carry germs, it is important to know that you are more likely to get these germs from other sources than your pet.

“However secure and well-regulated civilized life may become, bacteria, Protozoa, viruses, infected fleas, lice, ticks, mosquitoes, and bedbugs will always lurk in the shadows ready to pounce when neglect, poverty, famine, or war lets down the defenses.  And even in normal times they prey on the weak, the very young and the very old, living along with us, in mysterious obscurity waiting their opportunities” –Hans Zinsser 1934”

“The microbe is nothing; the terrain, everything.” – Louis Pasteur 1822-1895